C coders are defined by having seen a thousand languages go by and passed on all of them. C coders like C to the exclusion of all else, or they would have abandoned it long ago. Hare will not be picking up any substantial number of C coders.
Hare will not be picking up any C++ or Rust coders. It is a huge step down, offering literally none of what makes either language compelling for its users.
Likewise, Lisp and its offshoots. And Haskell, Erlang, MLs, APLs, Smalltalks, and Adas, all themselves niche.
Hare will not be picking up any Forth coders.
Zig is much more mature, and will maintain its lead. Nim is more mature, but will continue trailing Zig. Hare might chase after Zig alongside Nim.
The normal fate of any new language, absent The Miracle, is to fizzle. It is the certain fate of any language that brings nothing compelling to the table. Hare is exactly such a language.
A few people may continue using a fizzled language, indefinitely, like people maintaining their DVD collection. But there will be no reason for others to pay it any attention. The overwhelming bulk of the value in any language is network effects, and a fizzled language has none.