1. Do spam bots exist
2. Do "social bots" exist
For (1) the answer is clearly yes and nobody is claiming otherwise. However, academics don't see to care about spambots. That's a problem industrial researchers care about but not the sort of people who publish 'scientific' papers.
For (2) the correct answer is "there is no reliable evidence to support this". The term social bot is of course vague, but these papers are usually defining it as bots that attempt to subtly manipulate political discourse for ideological or geopolitical agendas. And when you go looking for evidence that such bots exist you end up finding what Gallwitz & Kreil found - that not just some of the research is bad, but all of it is. Where are the papers proving this problem actually exists in a clearly convincing way? There aren't any.
There's a very deep problem here which crops up in lots of other contexts e.g. why is there so much research into psionic abilities, why is COVID modelling so unreliable, why do scientific journals keep publishing auto-generated gibberish as "peer reviewed science" [1], why do so many papers in so many fields fail to replicate incl. not just social sciences but fields of critical importance like oncology? The root causes are the same, namely, academic institutions don't actually seem to care if research uses the scientific method or not. So you get things like Botometer as featured in this article, where it's just some ML model that's producing noise. It classified half of US Congress as bots and nobody cared. Thousands of papers have been published on the back of this model and zero have been retracted. It's because in that world what matters is publishing things that are interesting, not publishing things that are true.
[1] https://dailysceptic.org/2021/10/03/436-randomly-generated-p...