> Small companies and startups don't have the time or funding to do it.

I think this depends a lot on how you do the training. Sure, if you think of training as something very separate from the work, then doing lots of it could be expensive. But the last team I put together was very collaborative, with pair programming being the norm. In that environment, a lot of training comes essentially for free.

In a rapidly growing startup, I think building your processes with a strong bias toward staff development is the best way to scale. No matter how much experience a new person has, they still have very low knowledge of the product, the audience, local process choices, and the local code base. So startups always need to be educating their staff. Adding some technical education on top of that doesn't seem hard.

Personally, I've never quit a place where I'm still learning a lot. But I've hired plenty of people because they felt like they were stagnating in their current jobs.