In periods of ones life other things matters - maybe it is taking an education, starting a family, etc.
Other periods work matter.
It should be entirely fine to switch it on and off and change tracks throughout life - and in my view it seems like it is!
To reach a peak it takes roughly 10 years, but these 10 years can be started at 40 when your kids does not wear diapers anymore.
OP very much talks about this in the last few paragraphs, both in that you can't plan exactly and that you need to course correct as things change.
Also, just because it's okay or may happen that you change tracks within your career, it's still a good idea to optimize the track you are currently on and have an idea of where you want to be. Just coasting because you can't possibly plan your life seems like a strictly inferior option.
I thnk there is most satisfaction in putting yourself 100% into whatever you do. But what you do is not strictly limited to your work.
Sometimes you put yourself 100% into your family, sometimes it is education, and sometimes it is work.
While one can change tracks at any time, success is far from guaranteed. Being a distinguished engineer at 40, one cannot suddenly decide to enter the track for CFO or CEO. The track for that accepted entries 10 years back and is already over-subscribed. Only the CTO track is open at that point and only in certain companies.
You may argue you need employees to be a CEO rather than a consultant but you certainly don’t need a board of directors.
When one is 55 it is probably not too interest to attempt to go into the race to become and investment banker. Not because it is inherently impossible, but because there are more interesting opportunities.
Or at least: I think this narrative is the most productive, and the one I will stick to.
But your narrative implicitly signals acceptance of one's station and a realistic assessment of the tracks still open which is probably the right way to go.
I.e., it's probably affected by who bothers to voice their opinion, and how memorably, at different times.
But we will integrate with tech more, as a society.
I wonder where brick and mortar stores will be in 20 years.