I'm not saying that the existing situation is ideal and it's certainly not a dichotomy, but you have to consider the detriments as well as the benefits.
Then you have Stage 2, which would require an actual working implementation, so it can be properly tested and such. Acceptance in Stage 2 would result in the feature being in the standard.
Also I should add this is no different on wannabe C and C++ replacements, or most other programming languages with similar market share.
Go try to do a drive by pull request for a new language feature on those ecosystems.
But this would do nothing to introduce safety-related features, which are still sorely missing after 2+ decades. In light of upcoming regulation to exclude unsafe languages from certain new projects, maybe those features wouldn't be that unimportant after all.
The problem is that with the new wind C++ got with C++11, its role in GCC and LLVM, and domains like HPC, HFT, GPGPU, WG21 got up to 300 something members, everyone wanting to leave their name on a C++ standard, many proposing features in PDF form only.
And since in ISO driven languages, what gets into a standard, does so by votes, not technical implementation merit, it is about doing a proper campaign to get the bases to vote for your feature, while being persistent enough to keep the process going. Some features have more than 20 revisions on their proposal.