Sigh. Read your own link? Yes it’s not the same baseXX encoding with padding as any other.

It makes it not a straight 1:1 map unlike b64, and you need to be doing actual compute in order to get to the result. You are operating on blocks and calculating checks on each, etc. The algorithm isn’t complicated by any means but it’s certainly not the “second most basic translation task”.

And the CryptoNote variant is further different as it operates on 8 byte blocks. So you linked the wrong documentation.