if only it was this simple.
1. usually power outlets are standardised across countries (but there are countries where this is not the case and you'll find different plugs in the same country). two countries that share a border can have two or more completely different outlets/plugs.
2. power outlets are very simple devices. especially compared to usb-c.
3. but the G Plug is known to be one of the best, if not the best electrical plug. even so i think the chance of, for example, Denmark adopting this plug are close to zero.
so it's all very grey.
One massive downside of the type G plug (UK, Ireland, etc.) is its size. Most mobile charging adapters for phones or even laptops are 30-80% bigger, in my anecdotal experience, than the type A equivalent. The plug is well-designed from a safety and robustness perspective, and I appreciate that it's far better than the two-prong "Europlug" (for instance) at firmly attaching to a wall outlet, but it really should have been miniaturized.
The type L, J, and B plugs are far more compact as three-prong plugs go, even if they lack the third-prong shutter activation and fuse.
One example of progress on power outlets I know of is Denmark: Here the non-grounded plug has been compatible with Schuko outlets as used in most of the rest of Northern Europe, and Schuko connectors will fit in the outlets without ground connection.
Since most appliances come with Schuko plugs, a decision has been made for new installations to use the Schuko outlet, allowing a gradual transition to the Schuko standard.