The sooner we get https://github.com/tc39/proposal-type-annotations, the better.

Once we get it, there is still a solid decade before runtimes support it, and optimistically, still more 10 years minimum having to deal with an interpreted language that has acquired an unecessary build step.

I absolutely hated when PHP switched from a phpDoc culture with static analysis (and IDE inconsistencies that would click-take you to stubs as well) to actual types. Not because I hate types, but because of the transition period. Once it's gone, it's such a relief to get rid of unecessary docblocks.