Then your #2 concern should be "when will I want to access this data I store? How much of it? And how quickly?" because that's where Glacier can cost you a new house or car.

So for backups, stuff you don't need often (AND don't need to restore quickly), it's fine. Not so for most other use-cases.

Then R2 is worse for you than S3 as the entire point of R2 seems to be to do a different tradeoff than S3. You pay more for total storage but less for bandwidth with R2, and vice-versa for S3.