Many people complain that there should not be a level-limit to anvils. However, I have never encountered this issue IF I’m using it properly. I have made the perfect armor / tools with all the best enchants multiple times (on vanilla), and if you combine the books in the correct order, you never reach the limit.
I think the level cap is unnecessary, especially when repairing, also the whole process of combining books is a bit finicky and not very intuitive. I think they should ever so slightly rework that system, but without changing it too much