Not sure about studio quality, but for video conferencing and doing some Twitch streams, I’ve being using a Blue Yeti Nano USB microphone for a few years (since COVID) with no issues on Linux.
It’s unfortunate, but the reality is that many of the proprietary services are… free, convenient, and where the people are.
Most projects do not have a lot of funding, so it makes sense to use low cost platforms with the least amount of friction. I think most developers are aware of the risks and trade-offs, but make a pragmatic decision to use these proprietary services b/c the benefits for them outweigh the costs.
My friend has deployed Phorge for himself and appears to be happy with it.