I finally gave up on this. After installing the game to an SSD and that changing nothing, there's nothing more I can try.

I was thinking, if the cause of this problem was a change to the audio driver, all they needed to do is add an option for changing back to the old driver and maybe everything would be fine. Or would Endwalker new stuff really not work with the old driver?
Although that change would require an update of the client, I think it could pretty much be implemented at anytime, it shouldn't have to make us wait until the 21st.

Honestly, I'm kinda afraid that whatever fix they intend to add in 6.01 ("if any adjustments are needed") might really not work for everyone, just like some fixes that have been proposed by the community work for some people but not for most of them.

It really seems SE sees this as a minor problem, even though there are about 30 threads on this issue here on Lodestone, this one having over 200 comments and a few of them around 40-60, not to mention Reddit, YouTube etc.
Even though it's not really acceptable that we have to wait until the patch, it doesn't seem we have much choice.

If by the patch this isn't fixed though, I'll just have to leave the game…
It's very disappointing that'll have to abandon a game that's so special to me and did so good to my mental health through the last 2 years for such a stupid reason.
Even if I could afford a computer newer (and more expensive) than the one I currently have (which would only be possible for me like 6 months to 1 year from now), it would be such a waste to spend money on it only for the sake of Final Fantasy XIV, while most games I'm interested in still work in my current PC.
Which means that if this issue doesn't get fixed soon, it would probably take years for me to be able to return to the game…