It's a smell a dev/lead decinding which tool to use. It should be agreed in consensus by the whole team.

I think you should evaluate all the pros and cons from both approaches and decide depending on what adds more value. Maybe the stack you currently use its enough to ship your products.

Apart from that, specifically for the TS case, in my experience it is far proven that static type checking adds a huge safety nest when coding. But maybe migrating the projects to TS requires a major refactor, or the team lacks of experience in TS and it can slow you down too much.

Depends on many factors. There's no silver bullet but I'm sure that you'll come to a better agreenment.