Just to give context here, NodeJS doesnt support enums, namespaces and class parameter properties. All of these have been described as regrets by Anders Hejsberg, and none of them prevent advanced use of the type system at all.

Source: 49m 43s https://m.youtube.com/watch?v=NrEW7F2WCNA

Yes, they regret them because they hinder adoptions. Why? Because nobody chose to add TSC with all features in their runtime because TSC is extremely slow.

They know they can skyrocket adoption by limiting the language. That's the reason they regret it. This is just a strategy to increase adoption. Not because they are bad features. They are in fact very useful, and you should not stop using them just because your favorite runtime decided to go the easy way and only supporting a subset of TS by stripping types. You should rather switch the runtime instead of compromising your codebase.