Not really. My understanding of AI is far from grandiose, I know less about it than about my fields (Philo, BioAnthro) - I've merely read all of FHI, most of MIRI, half of AIMA, Paul's blog, maybe 4 popular and two technical books on related issues, Max 60 papers on AGI per se, I don't code, and I only have the coarse grained understanding of it. - But in this little research and time I had to look into it, I saw no convincing evidence for a cap on the level of sophistication that a system's cognitive abilities can achieve. I have also not seen very robust evidence that would countenance the hypothesis of a fast takeoff.

Beware the Dunning–Kruger effect.

Looking at the big picture, you could also say that there convincing evidence for a cap on the lifespan of a biological organism. Heck, some trees have been alive for over 10,000 years! Yet, once you look at the nitty-gritty details of biomedical research, it becomes clear that even adding just a few decades to the human lifespan is a very hard problem and researchers still largely don't know how to solve it.

It's the same for AGI. Maybe truly super-human AGI is physically impossible due to complexity reasons, but even if it is possible, developing it is a very hard problem and researchers still largely don't know how to solve it.