You’re ignoring the power of network effects - “shitty but widely adopted” makes “better but just starting adoption harder” to grow. Think about how long it takes to create a new HTTP standard - we’ve had 3 HTTP standards in the past 30 years, the first 19 of which so no major changes. HTTP/2 kind of saw no adoption in practice and HTTP/3 is still a mixed bag. In fact, most of the servers pretend HTTP/1 with layers in front converting the protocols.
Underestimate network effects and ossification at your own peril.