I’ve worked on internal tooling for companies for more than a decade now.

If you can get the right people, it is absolutely worth it. You gain complete alignment of incentives. You can easy access. You gain rapid turn around.

If you get the wrong devs, you also gain missed deadlines, a mess that is difficult to work with, solutions that don’t solve problems.

Basically, if you can hire the right people, it would almost certainly be worth it.