Basically. I mean the demand is there, but the developer recognizes a small island of architecture is a risk for long-term skill dev and wants compensation for that risk. For a developer to take the kind of gig that requires working bespoke air-gapped tech that sees few updates, they're going to want to be paid X+N over the median salary X (or have some guarantee of / expectation of job security).
It's a sucker's play to take the gig at price X, work on it for a year or two, and then get tossed to the curb when the project wraps with the only skills growth to show for it a combination of those ineffable fundamentals ("everything Turing-complete is fundamentally equivalent") that are useful forever (but can be picked up on any job) and some knowledge of Bob's House of Air-Gapped Machine's circa-1997 Flash install that their in-house kiosk infrastructure ran on.
There are jobs that'll pay for that Flash experience, but they're a lot harder to find than if Bob's House had been using some modern web architecture and you'd picked up, say, AWS experience.
It's a sucker's play to take the gig at price X, work on it for a year or two, and then get tossed to the curb when the project wraps with the only skills growth to show for it a combination of those ineffable fundamentals ("everything Turing-complete is fundamentally equivalent") that are useful forever (but can be picked up on any job) and some knowledge of Bob's House of Air-Gapped Machine's circa-1997 Flash install that their in-house kiosk infrastructure ran on.
There are jobs that'll pay for that Flash experience, but they're a lot harder to find than if Bob's House had been using some modern web architecture and you'd picked up, say, AWS experience.