Looking at the bhyve management UI and wondering, why would anyone use Free Pascal/Lazarus in 2025 as a FOSS contribution. Does it make sense to strive for job security in this context? Isn't the whole idea to be approachable to many people?

What is wrong with Free Pascal and Lazarus other than that it’s not in fashion? It’s probably the best cross platform RAD GUI builder in existence. It’s also very easy to learn, so it’s not really an issue of “job security” in practice.

There’s nothing wrong if you write something for yourself or you have a whole team of people who know it.

If you contribute to OSS you’d want your software to be maintainable by as many people as possible. Is this one person leaves, what should happen when no one wants to maintain their Lazarus app? Rewrite it?

Lazarus and Free Pascal are very easy to learn. A rewrite would not be necessary for another developer to pick it up and maintain it. It also has a larger community than you think. The official forums are very active.