100%. Another underappreciated point is that factoring connection is very misleading. That is, we don't know if factoring is equivalent to breaking RSA (in particular, the algorithms breaking low-exponent RSA (which one shouldn't use for a number of reasons) don't factor the modulus). It might be true that computing e-th roots (i.e. breaking RSA) is tractable while factoring is not.

Similarly, PKCS is complex but every part of PKCS is there because without it there is a concrete attack. Burt Kaliski (former chief scientist of RSA Labs) has an amazing talk which goes into detail about this: https://www.youtube.com/watch?v=sqsDKjPaJVg For example, why does RSA need randomized padding, besides the trivial IND-CPA violation? Because if you encrypt the same message to many recipients, the attacker can use Hastad's attack, which uses lattices in a deep way, to recover the message from non-randomized ciphertexts https://en.wikipedia.org/wiki/Coppersmith%27s_attack?useskin... Very much like an airline checklist in a way :-)

Another nugget in the talk: how RSA embedded a public key in their products and bootstrapped VeriSign! Can't recommend it highly enough.