Personally the hype over 5G is mostly that, so Europe isn't missing much with mmWave.
Considering you getting gigabit speeds requires you to be precisely standing on certain streets, I don't really see the point in hurting battery life chasing a signal.
Everyone gave Apple crap for not shipping a 5G phone even earlier, but the case for not shipping one back then remains the same as now—5G burns battery for relatively few real-world benefits depending on where you are. It's not like it makes the phones not a worthy upgrade—OLED on the regular 12 and better cameras are each probably a reason some people upgrade—but I don't think it makes sense to buy a 12 or 12 Pro if your main concern is 5G. By the time the networks are more mature and widespread, you'll be able to get a more power-efficient and more powerful iPhone. Such is the march of technology, and early adopters will always pay comparatively more for less as a tradeoff of being first.