I am using similarly “dumb” back-up system. I’ve two external USB HDDs, to which I copy my home folder every 4 to 6 months. The back-up folder currently has circa 250 GiB, but I don’t use any compression and I also probably do not have to back up my Steam library multiple times.

Yes, it doesn’t scale very well, but at the same time, I do not need to hoard 5 year old data. Yes, I should have an off-site back-up, but if my house burns down, I have bigger problems than losing my old photos.