This is one of the best reasons I've ever heard for not running iOS.
I completely understand why Apple won't allow it from a third party: that's a security and privacy nightmare.
I even somewhat understand why Apple hasn't developed such a feature themselves: it's a very minority use case and has some legal concerns in some jurisdictions.
But the end result is, yes, iOS is not for anyone that needs to record calls like that.
iOS will not let you do this natively, you have to add a call recording service via a three-way call whereas I can do this out of the box with /e/OS on a Fairphone.