I read the exact opposite: that they regret not using typescript for non-trivial projects because tsc would have prevented dumb mistakes due to a lack of types.

Correct. Small project turns into a bigger project, I think I can get through some complicated piece and BAM. I'm fighting silly typing issues and writing tests for stuff I would never have to do if I used typescript. While majority of my stuff is not that complicated, it seems there is always something.

I also wear a bunch of hats. So retaining all the new knowledge gets a bit hard. Sometimes its easier for me to fall back to patterns I used over the past 20 years of full stack development. If I had the time I would use typescript everywhere.

No, he's saying the opposite (as in TS scales better with project size).

> time spent fixing things that would have been caught [by Typescript] out weights the cons of using typescript

Correct. Most of my projects now and days are under 300hrs greenfield stuff. I do feel typescript can be a little more overhead to get started, once you have some well established patterns IMO its great for more enterprisey projects.