> Bare metal is almost entirely unnecessary in 2019, because you can configure Linux to only occupy one core for all of its processes and threads.

Configuring the Linux kernel just to meet the requirements for bare-metal applications might work for some use-cases but not for security and safety-critical applications.

For instance, the IoT industry still suffers from typical security issues in the drivers and firmware due to these Linux/Busybox vulnerabilities in the system. There are alternatives that use safer languages or formal verification that are more secure than configuring Linux for IoT or bare metal development, like TockOS [0] (using Rust) or seL4 microkernel (a formally verified microkernel).

So, is bare metal almost entirely unnecessary in 2019? Security wise, I'd much rather use safer languages like Rust for bare metal in 2019, than to use Linux/Busybox for this use-case.

[0] - https://www.tockos.org/