I've seen US startup people deal with manufacturing. There is a class gap that leaves no real space for skilled blue-collar work to exist and also be business critical, and fully integrated into the team. That is how a three-week turnaround for a milled prototype part ends up being tolerated.

You're completely ignoring the vast amounts thrown into a marketing funnel in an attempt to acquire customers for their usually meh products.

And engineering teams usually scale up with revenue as well.

I feel like your numbers are the myth that gets told not what actually often happens