Here’s my approach:

BORROW: hot new releases when I get on the hold list early. If everyone already knows about it, the wait is likely months or longer. For reference, I have an e-book hold that is likely to reach an anniversary of the date I put it on hold.

BUY: Physical copies of anything that I want to take my time with, including classics (I have format and translator preferences), books I am confident will be good reads for me (reading my way through Kazuo Ishiguro and Hilary Mantel), and books just not in my library’s system. Rarely I will get a frontlist I’m just excited about. I also preload my e-reader with just about anything I’m interested in when they’re on sale for 2.99 or so, since I use my e-reader primarily for travelling and my library is unreliable for availability of titles (see above, haha)

This has worked for me, I read 50-60 books per year but I’m not drowning in books, especially unread ones. The few unread titles I have waiting on my shelves I look forward to when I see them but the number isn’t overwhelming.

Figure out what works for you, don’t overthink it!