Unavoidable indeed.I would love to keep the original iOS that came either with my iPhone, iPad or Apple Watch ... but I can't. Now and then, devices are wiped and factory restored for a number of reasons. Now, how do I install the original iOS to the device a few years later? I can't. I have to install whatever iOS Apple allows me to be installed on my device.
Unless your stance is that outdated, unsecure, unsupported OS releases should be available. Which poses a HUGE security/stability risk for unaware users- should be available for download and use, then there is no way around this.
Before you say, yes, those OS releases should be supported.. Even Windows XP has now been dropped..