Many of the phone’s security features don’t only benefit the user - they also make widespread piracy virtually impossible, and they ensure that nobody can set up a rival software ecosystem on Apple’s hardware.
Your comment agrees with my world view (and why I even pointed out that "if you really want to insist..."), but comes across as an attempt to answer my question or refute my point, so I will then respond by saying "and giving a handful of security researchers the ability to run arbitrary software doesn't lead to rampant piracy" (but you know what does? the "free developer" tier added by the Swift team ;P).