If the dead internet theory were true or real, Google and Facebook would not generate so much revenue. Advertisers would notice that they are not getting any conversions and stop spending.
Are people responding to submissions, reposted by bots, a genuine interaction? It is one kind to know there are some bot accounts on reddit, and other to experience it first handed. For example, recently some karma farmer posted half of original post, and comments that appeared under it still referenced second page, because entire threads also got copied verbatim from previous submission, using different accounts.
It really feels like reddit admins don't do enough to combat that behaviour. Maybe, just like admin of PF, they think fake activity is better than none at all?