Lidarr is definitely worth a try (and also worth figuring out docker containers for).
Lidarr can be very effective at building a library, but be prepared for it to grab a bunch of stuff you maybe didn’t know you wanted and sometimes struggle to get that one specific album you need to go complete a set. It takes quite a bit of fiddling to get it going on it’s own. I’ve never really let it have free reign. I make it add torrents paused so that I can approve them individually and I don’t let it touch the part of my collection that I consider final and good. For example, I’d never want it to over write the stuff I ripped from my personal collection of physical media. So far as I can tell Lidarr is still also not the right tool if you have or want a bunch of live recordings or bootlegs.
I still buy a bunch of music, but now it’s almost all purchased as directly from the artists as I can reasonably manage; like live show merch tables, band websites, Bandcamp, etc. It wouldn’t be odd for me to grab a rip from Lidarr at the same time I buy a copy in my preferred physical format from the artist. Don’t forget to add that new stuff’s metadata to musicbrainz.org if it doesn’t already exist. Past me has definitely saved present me some hassle by doing this when I wanted to reorganize my library.