I have doubts about https://type-ruby.github.io/, but I do think their approach fundamentally makes sense (and #Python has kind of proven this). The slow adoption of Sorbet and RBS means that either there’s not enough demand or the existing solutions are not appealing enough.
I don’t really think that #Ruby needs static typing (I think they go against its spirit in a way), but I know that many people would disagree, so it’s good to have options.