Been there done that
I suspect I'm one of very few old enough on here to have actually worked through the entire process and come back around to the realization that there are many, many ways to do things, and a whole lot of them are totally, utterly, rubbish!
I've done 8008 assembly, AMD bit slice coding, 68000, TI 9900, Zetalisp, Common Lisp, Fortran, Pascal, Algol, Swift, Json, Basic, I digress. I've designed real time operating systems for aluminum smelters, air-to-air tracking radars, robot grippers, as well as PLCs.
Zetalisp was my favorite OS. Squeak comes in a close second. Would I like to live with them in the malware society of today? Hell no! VMS clusters ran the worlds wire transfers for decades. You kept them in locked rooms with extremely tight access. Why? Because with physical access you owned the world! Otherwise they were as bulletproof as anything today.
When DEC was pitching NT clustering, I had the privilege of pitching it to a major international bank IT department. The answer to the question, "Who uses DEC clustering anyway?," was, "You do in the wire transfer department." Response, "They don't let us in there." I stayed silent and didn't even smirk.