Some? I'd be shocked if it's less than 70% of everything AI-related in here.
For example a lot of pro-OpenAI astroturfing really wanted you to know that 5.3 scored better than opus on terminal-bench 2.0 this week, and a lot of Anthropic astroturfing likes to claim that all your issues with it will simply go away as soon as you switch to a $200/month plan (like you can't try Opus in the cheaper one and realise it's definitely not 10x better).
"some", where "some" is scaled to match the overwhelmingly unprecedented amount of money being thrown behind all this. plus all of this is about a literal astroturfing machine, capable of unprecedented scale and ability to hide, which it's extremely clearly being used for at scale elsewhere / by others.
so yeah, it wouldn't surprise me if it was well over most. I don't actually claim that it is over half here, I've run across quite a few of these kinds of people in real life as well. but it wouldn't surprise me.