Because Islam has not yet surpassed him and Islam doesn't mind sharing the shine. He doesn't see Khabib as his competition, so he doesn't mind being second best for now, and he also probably feels he needs to earn it first, before being called better than Khabib. It also still reflects great on the gym to call Khabib the GOAT. He is still a product of their gym, being retired doesn't change that..
it's just based on experience witth fighters talking about teammates and experience with people in general You should always be aware of biases and motivations behind actions, lest you want to be deceived. Look at how AKA and especially DC talked about Luke, while he is clearly far past his prime. And ask yourself how objective DC is when assessing Luke.
I'm not saying Khabib isn't great, bud. He is great. It's just that you don't seem to be aware of the biases of people if you think that you can make up for the early retirement and therefore lack of elite wins compared to other GOAT candidates, with anecdotes and statements from teammates and training footage.
If someone gets 'ragdolled' in sparring, you have no idea of the context of that clip in which he got ragdolled. Maybe the guy doing the ragdolling was completely fresh and the guy getting ragdolled was already training for an hour and might have been completely sore from doing strength training before. Maybe the guy who got ragdolled just wanted to try something new, for practice, but it didn't work out, because it's still new to him and the other guy could capatilize on that. While in an actual, real fight, most fighters are not going to use any move they aren't familiar and comfortable with.
You have to know the context of the facts, to know how to interpret the fact. Otherwise, you can't logically attach any strong conclussions to said facts. Training clips rarely, if ever, come with reliable context. And biases are definitely always part of the context that need to be taken into account.