There is only one way to keep a door opened for a newcomer or to restore some balance with citizen or state-sponsored software:

All critical/dominant/utility online services, where reasonable, should be provided with a "noscript/basic (x)html" portal.

You could find some exceptions: for instance in edge cases, a network protocol which would be open, _simpler_ than "noscript/basic (x)html", very stable in time (namely without "version breakage" all the time). Ofc, if those services require some account creation, it should be as easy than with big tech web engines. Those protocol specifications should be on a crawable text page on the public web (like the RFCs).

There is a negative price to interop: on smart phones, basic noscript/basic (x)html sites are likely to be ugly, more than on desktop.