I tried a couple of different websites and libraries. Also found this topic from 3.5 years ago - What are the current open source text-to-audio libraries?
It looks like nobody published anything in the last couple of years and most solutions are really really not good. Even Amazon sounds like some weird robot.
One of the best I tried is Coqui, but their best models were never published to GitHub. So TTS on their website sounds perfect, but you have to pay.
Also, ElevenLabs is amazing, but it is not open-source.
I cannot believe that there are no published models that sound good. I need it to generate a huge amount of text, so it will be very expensive to pay for subscriptions. They all charge about $5/20-40 min of speech and it sounds a little bit too much for me.
Could you recommend anything I can use for free? Preferably open-source, but not mandatory.