I’m similar to you. I recently went as far as to buy a pdf for an out of print book and then paid to have it printed and bound.

I suppose a remarkable would be another route but… they are pricey.

Same; avid reader of printed books here. I have more pdfs I can count (most coming from Humble Bundle impulse buying), but nothing beats physical books for me.

I got a remarkable pro, and it's just slightly better than screen. Being able to annotate books is actually a welcomed addition, and the screen is pretty decent. But flipping screen is slow (compared to a printed book), and going back and forth between pages is a hassle. Until we have the speed of a tablet (read: instant), with the screen quality of an e-ink, I don't think I'll voluntarily retire printed books.

Now, I have an O'Reilly subscription (two actually, through school and ACM), but the app is sadly horrendous, as OP mentioned. Hard to believe this is actually their core business.