I feel like the point is skipped in the post: if you ship TS sources, it means you need the TS compiler on the installed side, right? And specifically the right TS version for each installed package... which in some cases may mean conflicting requirements?
Author here. True, I think I should've worded it better. I work for Deno and it being a JS runtime that is able to run TS natively makes this less of an issue. The problem that a dependency needs a specific TS version hasn't come up so far. But that might be because Deno users tend to update to the latest version pretty frequently as we haven't done any breaking changes so far.
(If you own code is in JS, that is)