There is no way out of traditional UNIX shells, because most folks don't control the servers, and getting snowflake shells being adopted across the company and customers hardly works.
Also there are many UNIX deployments, where bash still isn't a given, one might be surprised with tsch or ksh.
You are right in the sense that Clang never replaced GCC on say Debian or Red Hat. As far as I remember, there are only a couple minor distros and one BSD that use Clang as the default.
So even though Clang is extremely compatible with all sorts of GCC quirks, inertia is still strong
And to probably 90% of people, Clang does the same thing as GCC. Probably 90% of people couldn't tell the difference between the two
But I think many people are glad Clang exists, e.g. it pushed GCC forward (at least in error messages, in modularity, and probably more)
And some people use ONLY Clang, not GCC
---
On YSH, most people do think there needs to be a "clean slate" successor language to shell, and that's what YSH is aiming for. Notably, it's informed by re-implementing almost all of bash from scratch, and shares the same runtime
The reasoning behind that is that I noticed that sort of like "make replacements", many alternative shells [1] are better in one dimension than their predecessor, but worse in other dimensions.
Our goal is to be better in all dimensions, so a superset is a good way to achieve that. We learned the hard way that these 30-, 40-, 50- year old tools have very diverse users and usages - i.e. most people might use 10% of the features, but across all users, that's 100% of the features
Nonetheless, OSH has been the most bash-compatible shell, by a mile, for a few years, and it's only getting more compatible. How fast it converges depends on contributions, and we're getting good PRs, but can always use more
YSH also has a bunch of users that are providing great feedback, and helping to make it stable
(blog author here) That is the kind of thinking which just unnecessarily gatekeeps innovation.
There's always someone "in control" of a server. But even more important, there's always someone (or usually a group) in control of deciding which shell should be the default on an OS. And these are the people that should be reached somehow.
And Oils is just as much a snowflake as Bash, Tcsh or Ksh. All of them are POSIX compliant (though not sure with tcsh), all of them bring own additional features. But the only shell with additional features which don't suck (by being 30yo) is from the Oils project.
Also there are many UNIX deployments, where bash still isn't a given, one might be surprised with tsch or ksh.