That's certainly a good point. Languages usually change slowly, though, so once a good baseline grammar is in place, maintenance is unlikely to be a huge load

That's certainly a good point. Languages usually change slowly, though, so once a good baseline grammar is in place, maintenance is unlikely to be a huge load. Furthermore, with tools like tree-sitter and the language server protocol, multiple communities benefit from their continued existence, so there's a bigger pool of contributors to the parser.