Another example might be when startx stopped working for non-root users - a "change / why / what to do now" explanation would have been handy.
But OpenBSD isn't aimed at Unix newbies so it's entirely understandable why that level of hand-holding doesn't exist.
Also, I installed Kubuntu the other day, and I just kept pressing enter.
There was even a checkbox for FDE.
OpenBSD's approach appeals to me aesthetically, and I like the feeling that I could easily dive in and get to the bottom of the stack. There is no magic.
By contrast, I look at Ubuntu as a hot mess of code that I'll never understand, while simultaneously appreciating that I can click through the installer after a cocktail or two and be playing games on Steam in short order.
spending time make systems backwards compatible should be better spend making the path to using <newthing> as easy as possible, and a big help in that is keeping complexity down and not building towers of abstraction.
https://www.openbsd.org/faq/faq14.html#softraidFDE
Granted it could probably be added to the installer, but that's hardly "Utterly complicated to setup".