For programmer or engineer though, it's now a gamble to invest heavily and be that expert in a single technology. In medicine, expert/specialists have large pop

For programmer or engineer though, it's now a gamble to invest heavily and be that expert in a single technology. In medicine, expert/specialists have large population pools and simply accident or genetic defect rates they can rely on to have customers for their speciality. You can specialize on a specific body part and become a dentist or ophthalmologist and be assured there will be sick people who need you and are willing to pay (unless of course we cure/eliminate the problem you solve which rarely happens). If you're in software and know the internal workings of Postgres, well that's fine and dandy iff a business decides to use Postgres. Maybe they chose MariaDB or something else arbitrary instead. That highly specialized knowledge you have about Postgres is highly dependent on demand as it always has been. The difference now is that for any given technology, there seem to be a sea of competing options, so the risk of your expert time investment having no demand is quite high. The salaries may be high but I'd argue they're not high enough for the time, effort, and risk to become a specific technology expert anymore. I have expert level knowledge in systems that now have almost no demand. It's a waste of my time to maintain them at this point, the risk and opportunity cost is far far too high. There was a time when you could become an expert or near expert of about 1-3 competitors for a specific library of infrastructure and those skills were incredibly valuable, highly transferable, and in demand because the pool of competing tech was so low. Now I can't even keep track of number of just say database or database like applications teams may choose to use. There's more diversity than there is demand to justify and sustain the evel of diversity we now have, IMO.