I see your point with single application. However, do not you think that, for example, highly stripped special purpose kernel and distribution built with let's

I see your point with single application. However, do not you think that, for example, highly stripped special purpose kernel and distribution built with let's say buildroot will do the job equally well? The advantage is that it will run on bare metal (without supervisor or any other type of micro-kernel to manage microserviceS). If there will be the need for the second application, the bunch of functionality will be shared and hardware resources will be used way more efficient. Also, I am wondering if it would be better to spend resources addressing existing issues with OSs (like not strong enough security, etc.) instead of just giving up and hope that supervisors/micro-kernel will do it better?