Earlier quoted context omitted.
easy to switch , not easy to own.
If by "not easy" you mean "a couple of years", sure. Don't mistake what I'm saying. I'm using the word "own" rhetorically. Obviously there will be no point in your career where you are likely to be the world's leading expert on computer vision. What you're aiming for is to be the leading expert that is available to employers within a reasonable amount of time at the level of compensation you're hoping for . It's a sp…
But the few people who are really hiring people who "own" CV want PHDs with a relevant thesis and you're not going to get one of those working weeknights after the kids go to bed.
Meanwhile people pursuing PHDs have no idea if their area of research is going to be hot in industry when they're done.
Granted, a lucky few people who follow the autodidactical route may find themselves authors of a really popular OSS project. Or they may be able to luck or maneuver themselves into a position at their current employer working in a capacity that future employers will see as "relevant industry experience." Obviously this is hardly a sure thing and if they plan it wrong or just get unlucky they're not going to have a nice outcome.