On that note I beleive GCC 2.95.3 (released 2001) is the last gcc written in C, therefore one of the most important versions and still used for bootstrapping
I never understood why one would subject themselves to bootstrap a system using this method instead of simply cross compiling?
Cross compiling only helps with a subset of uses.
If you're doing it for security reasons (to counter the Trusting Trust attack), you aren't coming from another current-edition GCC/clang, you're coming from the simplest compiler you could find.