It's good that no government mandates one specific technology then. This regulation is essentially "the industry needs to agree on one approach or else" - when there's need to change, they can re-evaluate.

Sometimes that is good. The EU power plug is probably better than the earlier US standard one, but it isn't enough better to switch everything i own to use it. (220 vs 120 volts is an issue that i'll ignore for this discussion). I'm sure engineers could do better than the EU plug, but not enough they would switch.

You just sell to industrial customers first. Look at AC power outlets, they're heavily standardized but also regional. It doesn't inhibit the existence of other power delivery options for customers with special needs, there just isn't much consumer demand because standard outlet designs as Good Enough for most people's actual needs.