It Catalina is any indication, Apple is doing users a favor by precluding them from upgrading to Big Sur.
I guess you could say that if Apple was selling Macs in record numbers, which they are not!
They still have no product I want, so my Mac Pro 4,1 (5,1 firmware) will continue to live and be upgraded.
So we beat on, boats against the current, borne back ceaselessly into the past.