So once in a lifetime? Sure. But if people do this routinely, the planet pays, which means someone somewhere pays. Our environmental debt is like a maxed-out bank loan at this point. And those people will paying the price will almost all be poor. Tell me what's more likely: a future where the poor get to fly to Italy every year, or a future where the rich and not-quite-rich do that until we really do run out of room on climate.
In my city we're using electric two-wheelers increasingly. It requires good road design, low speed limits (20mph or even 25kph), high standard of driver training, and well-designed vehicles with good brakes etc. With those things in place, it's possible to operate them safely, and on 1/20th the energy budget of full-sized EVs. 20mph doesn't sound like much, but in a big city it's fast enough to cover a lot of ground, and do so in relative safety.
Growing up, I have always wanted to go and spend time in Italy. I am sure that there are countless other folks, from places emerging from the shadows of war, pestilence and suffering with similar dreams.
Who are we to say that no, you should instead go tour only places nearby?
Whenever there is scarcity of anything, the rich rarely suffer, but the farmer in rural rayalseema will go without. I fear that if we bake in this "encouragement" into costs of electricity (say), it is not a software engineer who will go drive in a moped, but a day labourer.
The issue with mopeds is not just that you consume less electricity, but that you put your life at risk!
At the risk of digressing, I am all for getting rid of two wheelers for non recreational use. They are bloody death traps (A person dying on a moped or bike does not even make local news in india). In my family alone, we have lost 3 cousins from my father's side to two wheele accidents) So no, not overbuilding only means that poor suffer more, for no good reason.