Dunno about this one. This is very much so FAANG type of thinking, not really (newer) startup type of thinking. Sacrificing a few man-months to training is something that is hard to do when that's a significant percent of your remaining runway.
I agree, but it's also a matter of degree and availability of the skill you're looking for in the market. I wouldn't hire a developer who has only touched Java to do React when there's lots of React developers out there, but as a Rust shop I'm happy to talk to a Go developer who seems open to learning Rust on the job.
Dunno about this one. This is very much so FAANG type of thinking, not really (newer) startup type of thinking. Sacrificing a few man-months to training is something that is hard to do when that's a significant percent of your remaining runway.