You’re not alone, I definitely spent the majority of my time on 720p rips. I couldn’t tell the difference between them and 1080. Though these days, actually just recently, I’ve switched over to 1080, and I can tell when it’s lower.
But most my collection is still 720 and I feel no need to go back through and update everything. Maybe when I get arr set up I’ll let it go through and do it for me 🤷♂️