Meaning Msft Principal is below L5? I got the same feedback from one of my friends who works at Google. She said quality of former MSFT engineers now working at Google was noticeably lower.
I mean, _now_, sure, I'd assume Microsoft Principals should be hired around L4 at Google. But that's just due to a temporary inbalance in the decline of legacy organizations. Give it a few years and it will even back out and msft 64 will be in the middle of L5 range like levels.fyi claims.
But even so, an L5 at Google is basically a nobody as far as prestige or convincing other people to adopt your plan goes. Even L6 is basically just an expert across several mostly local teams. L7 is where the prestige gets going.