You’d only need multiple cables if you we’re charging/using each device at the same time.
When I travel, I have probably 5 USB-C devices with me. I only take 2 cables though, and the second one is a ‘just in case’ cable. Rarely do I need to charge all of the devices at the same time. Particularly with the fast charging speeds of many devices now.
But that’s me, we’re all different - thankfully. I’m just saying, because you may need all of those cables and adapters all at once, we don’t all do the same.
Personally I couldn’t give much of a figs fart either way. But it would be nice to cut down on having to take Lightning cables with me just for my phone and headphones and use a standard interface.
I don’t however, think that a governing body such as the EU are the ones to decide on it though.
If there was to be a standardised connector, then it should be the electronic companies as a whole to make that decision.