Well, what you said about Jon Jones can just as well apply to the female fighters --- they weren't physically on their prime, their hunger isn't the same as when they were younger, new athletes that bring in new skills, that have better stamina, that have analysed the older ones' fights over and over and so coaches are always bringing new strategies to handle what others could not... it's not like it is only applied to men.
Jon Jones said that Thiago Santos was trying to give him brain damage in that fight and take years of his life, so if fucking up his knees are a trade off for that, he doesn't care if he limps for the rest of his life. Recently, he said that he'd get really mad when he'd get home and have concussions, thinking he did something wrong through ought his career --- emphasizing how being hit over and over takes away an opponents ability to counter simple things they'd be able to do so easily before... So while not directly stated, it is a fair assumption that may add to his more cautious approach.
I never said that couldn't be applied to these female fighters as well, those are all fair points. I even admitted as such:
The examples I gave of these female champs (Valentina/Nunes) feature some elements of this as well, so it's not a lightning in a bottle scenario.
All I said was Val and Nunes never adjusted their styles to not try and finish opponents, it's just the opponents got a lot better and their styles didn't allow it because people think Val is some great kickboxer when she's actually a better grappler and Nunes is always worried about gassing.
I've seen all of their fights and I think it's pretty objectively true, lets just look at their recent records:
VALENTINA (defensive average kickboxer + solid wrestler/grappler)
Grasso 3 - since she couldn't finish her in the two first fights standing and got robbed by the judges in the second fight she chose to just outwrestle/out-grapple her to guarantee victory (Grasso is a good defensive grappler but shit wrestler), Val definitely fought "safe" her as a result of the last 2 fights.
Grasso 2 - definitely was trying to finish her throughout, she just doesn't have the power to one-hit someone unless they are Jessica Eye and Grasso has dangerous boxing (better striker than earlier opponents)
Grasso 1 - definitely trying to finish, went to hard throwing spinning shit and got her back taken and choked out
Santos - definitely trying to finish but Santos is huge/better athlete than most of her opponents and gave her hell early
Murphy - Bad athlete with low-level stand-up, put a beating on her and broke her easily
Andrade - Bad defensive grappler, took her down and elbowed her face in
Maia - Strong boxing but shit wrestling (good grappling though), took her down and controlled her
Chookigian - Similar to Murphy, not elite athlete and poor stand-up, beat the piss out of her
Carmouche - Dangerous vet and good athlete, did what she needed to do to win
Eye - Terrible stand-up, Val head-kicked her to shit
(finished 4 of 8 opponents)
I don't want to do her entire career, but the point is when she fights lower level athletes or people with glaring holes in stand-up/grappliing she can overwhelm them there, but she's never been a "born finisher" she just can do it when she has a huge technique advantage because her style is a defensive outside kickboxer that has good wrestling/grappling. I don't find it shocking that when she runs her A game of wrestling/grappling on good grapplers she can't finish them; when she can run her B game of stand-up on shitty strikers she does.
NUNES (power-brawler athlete with decent submission grappling)
Aldana - Beat the piss out of her for 5 rounds, didn't want to gas so cruised
Pena 2 - Beat the piss out of her for 5 rounds, didn't want to gas so cruised as best she cold
Pena 1 - Gassed hard going for the finish early, got finished in the second because of it
Anderson - Bad fighter, took her to school and destroyed her early with stand-up+grappling
Spencer - Tough stand-up fighter with solid defensive grappling, got cut early so was forced to fight safe to control the pace of the fight
GDR - Put a beating on her but almost gassed because of it and upkicked/triangled late in the fight, decided to cruise
Holm - Headkicked her to shit
Pennington - Controlled demolition, finished her in the 5th on cruise control
Valentina - Good athlete with decent stand-up and solid grappling, didn't want to gas so fought safe and cruised to a split
Rousey - Blitzed her early and got a first round KO easy
Tate - Blitzed her early and broke her nose, subbed her on the ground
(finished 5 of 10 opponents)
Agains I don't want to do her entire career, same point as Val though - when she fights people that are lower level athletes and she has a huge skill advantage in the stand-up in she destroys them, but she is afraid of gassing because that's how she loses (Pena 1/Zingano), so against fighters tough enough to take the beating she takes her foot off the gas in order to not put herself in a position to lose. She never changes her style up unless it's the result of fear of gassing.
Both Val and Amanda finished 50% of their most recent opponents, it just so happens they had to have some rematches against really tough fighters for them stylistically where since they lost the first fight they had to adjust heavily to fight safer in the rematches. Outside of those fights they've typically always fought the same and consistently and even with them fighting "safer" in rematches they still have a 50% opponent finish rate.
I'm sure Jones said that, but he already has brain damage from all the sparring and the few wars he did have with Gus 1/DC 2 and some random hard shots throughout his career (Evans headkick/Lyoto early blitzes, etc.). Jones dropped Santos with an elbow at one point and was definitely hunting him, he just was worried about the power/speed so he chose to fight "Safe" which again, that's what elite fighters do when they are against highly skilled opponents that overmatch them in one area - it's not like they don't want to finish them, they are just trying to take the safest path to do so.
Outside of Val lay n' praying Grasso in the 3rd fight I don't really see many examples of them just doing nothing and taking a W with zero risk.