The problem is that sel4 isn't turnkey enough for the average product maker to use. It's good for larger firms who can invest in building out their own platform on top which they can then use in products. There doesn't seem to be anyone building a public platform on top of sel4 which can be then used by product makers. This is similar to building a product with a custom Linux distro vs an existing one, albeit a custom Linux distro is still far easier to do because of the great ecosystem around it. I'm not an advocate for using Linux, but unless someone invests in the missing pieces, sel4 usage will never become widespread.
> unless someone invests in the missing pieces, sel4 usage will never become widespread.
There's multiple efforts, such as Makatea[0], Genode[1] and sel4cp[2].
The seL4 foundation is finally well-established and funded thanks to increasing commercial interest[3]. There's been a lot of activity lately[4] and I'm very optimistic for it.
