> I find most niche / less popular languages lack the developer tools ecosystem in ways that simply hinders adoption by more devs.

Niche languages often serve specific purposes that don't require broad tooling. They also sometimes can leverage tooling from more popular languages. Less popular doesn't necessarily mean less capable - some niche languages have excellent tooling in their domain. Not to mention that not all developers need the same type of tooling or prioritize certain set of tools equally, like for example, for me personally - homoiconicity and REPL-connectivity in a language are far more important than LSP or some other things.