I can teach 100% of the tech stack to a total noob in a matter of weeks. Trial by example is my lesson of choice these days. The good apprentice will absorb these like a dry sponge to water.
It also really helps that our tech stack is simple and fits on 1 computer. It is not bullshit abstraction either - You install 3 things on a fresh Win10 box to promote it to "Official Developer Machine" status. None of these things happens to be Docker or any other containerization tech, so even junior developers are expected to understand how the product runs on the bare metal/vm. Spoiler: It's 1 process & 1 service so they learn it fast.
Basically what I am trying to say is that your ability to consume non-PhD candidates is partially predicated upon how you've decided to run your tech business. If you (ab)use enterprise arch like message buses, event sourcing, et. al., you are going to find that it requires additional mountain ranges worth of background knowledge to understand how these things fit together. If your tech stack can be considered within the context of a single process, the margin of understanding becomes much more practical to work with in my experience.
Honestly, I almost prefer to start with a blank slate these days. Don't know how a computer works? Fucking fantastic! I can probably still get you productive in my simple C#/SQLite tech stack faster than if I had to de-program some web-scale zealot for the same purpose.