Believing Khabib to be the GOAT is perfectly reasonable and defensible, but announcing that the best three fight streak is the definitive metric is completely arbitrary.
Also, I’ll point out that inactivity contributed to the high rankings those guys had. At all times, Conor, DP and Justin were contenders, not the best lightweight on the planet. Arguably they weren’t even number two, at least until Gaethje defeated Tony. They acquired belts only because Khabib didn’t compete regularly enough, and by having belts they got ranked ahead of the second and third best contenders in other divisions. Not only did Khabib benefit from all that time off, both in terms of not taking damage and not risking defeat, but the quality of his wins appears better as well.
In terms of three best wins in a row though, I do agree that this is a very strong contender.
Jones had a ton of dominant wins, but there isn’t really a run of three that stands out the way Khabib’s last three does.
The Gus and Cormier wins had Glover in between, who wasn’t at the level at that Khabib’s guys were, and the wins were competitive. Rua Rampage Machida was very good, and now that I’m typing this they were all undisputed champions at one time and were destroyed by Jones, so I think that’s probably better (and when you add Evans that’s FOUR undisputed champs in a row, which brings us back to the point about how arbitrary a three fight streak is).
Not sure what GSP’s best trio is, perhaps Fitch Penn Alves. Fitch was clearly the second best welterweight for a long time (much more clearly than CM/DP/JG were in my view), Alves was right behind him, and BJ was a two division champ.
Marquardt Franklin Henderson is better for sure. Hendo two division Pride champ, Franklin very solid UFC champ, Marquardt the clear beat rising contender, and he smashed them all quickly.
And of course the elephant in the room vis a vis the GOAT debate is that Khabib’s trio of wins also happens to double as his only defenses.