I accepted an offer for a new job yesterday and so I won’t need that buffer but I’m keeping it, ISA’s and pensions are all good but I didn’t leave myself enough readily accessible cash to just say fuck it and walk if I needed to.
There is, of course a trade-off, which I'll illustrate with our situation. I'll only hire full stack developers, by which I mean people who are willing to turn their hand to anything in our systems, because it gives us more flexibility in terms of building teams, working across sytems, providing support, and so on. But we're a relatively small tech organisation with a lot of demands on us and so need that flexibility. People obviously have areas of specialty, but broadly they'll poke around in any system they need to.
I'm not saying you're wrong: not at all. Just that the trade-off is perhaps more limited options. That may not be a bad thing if they're not options you want though.
I do the same, it's amazing how well it works. As long as you genuinely try putting (what you think is) the company interest first, people actually appreciate you more if you don't do what you're told, but what you think is best. At least that's my experience so far. And it makes sense - because not everybody can afford to challenge the status quo & conventional wisdom, people that can do it can become very valuable.
A very experienced dep/ops in extrimis should be able to hack code even if there is no installed editor - I have recovered a stuck systems by editing config files with awk.
Indeed I never hide my ability to do so and I try to make very clear the things "I won't do" at any gig I take. Either before I start or very early in the process. At my current job it is "I won't program in a language without both types and IDE". Because of this I only work on the parts that are in TypeScript and the the JS, Ruby and Python parts are other people's problems.
I may seem like an asshole, but so far it works. Almost a year later I haven't been fired. And they seem happy about my work. And I am definitely not near burnout. Stark contrast with the older days.