Antiquated? Hardly. Look no further than the strength of Discogs to understand physical media still has much value. I purchase used LP’s all the time, and also occasionally a CD here and there, but not as much as LP’s. Heck, I still occasionally buy cassette tapes if I know they are quality (late 80’s into the 90’s were what I feel the ‘golden age’ for cassettes).
My preference is still physical media, and I know I am not alone.
It would take time, (it does, I’ve done it), but you might want to consider cataloging your collection on Discogs, you might be surprised their value in total.