I often recommend conda to folks when I think it’ll be useful to them, but I don’t use it myself, so I guess I can answer that part.
The reason is pretty simple… all the packages I need are distributed through PyPI first, and have wheels or are otherwise easy to install on my system. And, since my packages are also distributed through PyPI first, all my package metadata (e.g. dependencies) is expressed in terms of PyPI packages. So if I switched to conda, the only differences to my life would be that I’d have access to fewer packages, and they’d be more out-of-date, and I’d have to maintain two copies of my metadata (one for conda and one for PyPI).
These are inevitable downsides of conda acting as a middle-man. There are also lots of advantages to having a middle-man doing integration testing etc., but those are solving problems that I don’t personally have, so for me it’s all downsides.
You should also check out this post I wrote that’s ostensibly about lockfiles and workflow tools, but has a long digression about how pip and conda interrelate, why the two sides aren’t good at talking to each other, and how that could be fixed: