I find it's weird they changed dynamic rule to static rate since static rate cover fewer user error.
Because it's not really designed to cover user error, but rather, software error. There is more discussion about it here (
https://github.com/bitcoin/bitcoin/pull/16539), particularly this comment by Greg Maxwell here (
https://github.com/bitcoin/bitcoin/pull/16539#issuecomment-578432863).
In short, if I wanted to make a high priority transaction and pay, say, 200 sats/vbyte, and my wallet then tried to include 500 additional inputs because of some bug, then a flat rate limit would prevent that from happening, while a feerate limit would not.
