I'm entirely mystified how people can get pip to work for anything that isn't either quite simple
or is a shrink-wrapped product with carefully, and manually, selected versions of every component.
Anyway, conda isn't really aimed at either of these scenarios. It's aimed at people doing research, data science, etc, where you are likely to use a sprawling assortment of packages, many of bewildering complexity, and entirely without the time to tinker with which package version works with which.
The naive algorithm that pip use, which essentially is to grab the latest version of everything often doesn't cut it in these scenarios. Conda, with all it's warts, actually does dependency resolution, which it's why it's so much "slower", it does something completely different from pip.
As pip and conda can coexist today, I simply install what's not available in conda/conda-forge with pip, and have a much easier time manage all my dependencies.
If you do anything in data science, or similar, it's rarely a problem that things doesn't exist in conda, because they almost always do, which is not the case with all kinds of packages.