From observation, Twitter seems to have the worst bot:person ratio. Reddit feels like it has more bots then ever as well now with a lot of accounts either being fresh or getting suspended. YouTube, I don't even look at comments but probably garbage.
So yeah, it exists but to what degree?
I say that because I believe there are a lot of devs who really want that stuff to be true. They want to be able to perform better, they want to do less "boring work" so they can move on to bigger things and so on. And just like a person can be a fan of a sports team, a form of brand loyalty, I can certainly see people forming the same relationships with AI brands for $REASON. I don't doubt AI brand fans exist. Humans get sentimental and attached to things. Especially things that they perceive as having helped them.
Well you have people who work in vocational jobs who develop brand loyalties to tools such as John Deere, Caterpillar, Snap On, and so on. These companies sell branded merchandise such as apparel and other trinkets to promote the brand via their fans. Visit a vocational forum and you will see how people can be rabid tool brand fanatics, smack talking each others favorite tool brands.
I do believe there is AI shilling for sure. But I also believe there are people who really want AI to level the playing field for them so they too can be/feel like a 10x engineer or whatever. They invest themselves in the technology using a branded product which they can form an emotional attachment (e.g. Claude helped me feed my family. Thanks Claude!) So you get these gushy posts that feel like shilling but might be an emotional outburst of support for their favorite brand.