That is an interesting idea. But like you said, it takes time for you to get good at your job and more importantly, it takes time for you to increase you earnings. I don't know how feasible it would be for a senior developer making $200K per year to start off as an electrician's apprentice at $50K per year. Especially when you have a mortgage and family to provide for.
The only way your idea would work if somehow work and income were divorced from each other. That seems rather utopian than practical. Maybe if you were wealthy enough, you could try out multiple careers. Or maybe wait til retirement though that also seems impractical.
I suppose it all depends on what an individual wants to optimize for. If one wants to optimize their life for happiness, then changing careers is an option even if it means less money. But if one wants to optimize for money/title etc (which is what most people do, right or wrong) then it is better to stick to one career and get as good at it as possible.
Or if one lived more modestly. If the person making $200k/year lives on $100k/year and saves the rest, they'd still need to cut back a bit to drop to $50k/year, but not nearly so much.
Mortgage and family would make that more difficult, but from my perspective ($80k/year, single, and quite comfortably not spending even half of that), $200k/year certainly sounds "wealthy enough" to me.
The only way your idea would work if somehow work and income were divorced from each other. That seems rather utopian than practical. Maybe if you were wealthy enough, you could try out multiple careers. Or maybe wait til retirement though that also seems impractical.