I didn't say it's useless, I said it's a niche utility. There are, what, 10 even slightly commonly used shells?

Compared to the thousands of other programs that spawn processes, I think shells count as a niche use.

If fork() and exec() had been kept as the niche utilities they are in addition to a more commonly used spawn() syscall, fork() and exec() could have remained simple and small, and not needed all the CoW magic and many other complex features at all.