I did cut back significantly since that initial switch. At one point, I had 1TB of music. Right now it's sitting at ~210MB of mp3s. Quod Libet uses less RAM than Firefox, Thunderbird, or RSSHub, but it is sitting at 4th place on my system.
I don't think there's a way to scale music libraries to these obscene sizes without impacting RAM. Unless you manage it strictly with a file manager and open album folders individually with a lightweight player used only for playback.
nodejs + thousands of feeds processed every hour, so I'm gonna go with yes
Firefox is for opening links that appear in Thunderbird with my current workflow, RSSHub generates the vast majority of them