I somewhat agree with your point, but the I think software developers underestimate the difficulty in getting someone up to speed when the "tech stack delta" is

I somewhat agree with your point, but the I think software developers underestimate the difficulty in getting someone up to speed when the "tech stack delta" is significant. Every piece of technology you need to learn isn't a linear increase in time, but rather more quadratic. Learning just k8s might take N weeks, and learning Go might take M weeks, but learning k8s and Go at the same time takes more than N+M weeks, and might take something more like N X M weeks (or really 0.1N X 0.1M or something). Learning one tech while also learning another tech makes each more difficult. I push employers to understand this and instead of throwing people into the tech pile, have them hit each tech bit one at a time, but the sink-or-swim belief is strong.