Foobar2000 is what I use for all of my conversion in Windows. Wavelab and Reaper both do batch processing and conversion but usually it’s quicker to just load everything into a Foobar2000 playlist, selecting it al, right clicking and choosing one of my conversion presets. There’s a SoX sample rate conversion plugin for it if you want to get picky about your SRC.
Reaper’s batch processor can do a lot more. Wavelab’s is probably the deepest but kind of clunky and Wavelab is pretty overpriced in 2021 (I only have a license because I needed it for work quite a few years ago; haven’t updated since 2015 and hardly use it anymore because 99.9% of the stuff I needed it for can be done with Reaper now).
EDIT: for editing, processing and tagging samples, creating chains, etc. I’d say again Reaper (although I actually again use Foobar2000 for most of my tagging). For cataloging and file management it’s maybe not the best choice, it has a perfectly decent file explorer but if there’s any kind of advanced file management I haven’t learned about it yet. It’s very possible if not likely that someone has developed an addon.