It was partly that I didn't want to advance my business into larger and larger projects that would have required me to either travel a bunch or hire coders under me, because I found the pocket I liked - a remote contractor/consultant that architects and delivers. And it partly might have been the reality that some of these technical skills are just becoming more commoditized.
But either way, for me it didn't really scale past a particular point. I ended up having a metaphorical rolodex of past clients that were all interested in hiring me as a hands-on-architect-level employee but wouldn't offer contracts, and I eventually accepted an employment offer as my last contract dried up.
I started with php/java, and had previously spent significant energy learning more functional/distributed-computing concepts and Scala/Akka, had a couple of good contracts with them too, but those skills are withering a bit while my current employer is paying me to bone up on React and Node of all things. At least I can influence my team to adopt more FP concepts. I miss Akka.
So, I don't know. As you get older, you get more skilled and senior, but that can top out (in terms of $$ benefit) long before retirement if you're not one of the very rare superstars. And the benefits of being senior are not easily measured and aren't really rewarded - for many hiring decisions, they're just looking for a tech stack - who cares if you're twice as effective on average if they can hire someone average for 80% of your salary? They don't have the counterfactual, they'll never know, they think they saved money. And if you look at entry-level salaries vs senior-level salaries, there's not a huge spread there, not on average. I make maybe 2x-3x what entry level salaries are now, and that's at the top of the salary band for senior level architects where I'm at. And big companies will continue to look for ways to take chomps out of the top end and tighten that range.