Why not have privacy on the base layer?
Discussion
Bitcoin has a 15 year record of running as it is. You change the code this much, you start over from zero.
You know what else has a record of being as it is? Government.
Government always being as it is means paper required to print all the laws and regulations hasn't changed. The problems we face are mostly derived from the fact that government has changed. Towards totalitarian and hyper centralised