Just the economic and yeah, transportation infrastructure we have in Europe won't support that. It's not even the population density really.
Until we invent teleportation, putting everyone in their own separate house is unsustainable.
Having lived in a European city I was appalled of how bad the air quality was, how noisy the streets were, how annoying trash collection at 5am was, I had to use a wet mop on the hardwood floor almost on a daily basis to and it was black every day. I had to walk a half a mile to a tiny parklet, always packed with kids as it was the only location in the play. Every morning on the packed subway and street buses. It was awful, I couldn't wait to get back home.
Back home I live in a green environment, trees everywhere, I got my lawn, there are no fences, I forget to close my garage door at night no problem, nothing is ever missing ... I use a wet mop every other week and it is never dirty.
Do you know what generates the CO2 emissions? All that useless junk we buy shipped from all corners of the world. The fix is buying less junk not blaming on someone that happens to want to live in a green environment.
I know it's hard to be criticized for your lifestyle, but please do your research, suburbans lifestyle is nowhere near sustainable. That's not anecdata, that's data.
I don't actually live in the suburbs, just a small town that looks like a suburb, and I also lived in European style cities hence I understand the attractiveness of a suburb. It is a different lifestyle and you can't "fix" the suburbs with the wrong kind of arguments - "you my friend suck for wanting to live there" Find a suburb looking place in Europe and check the prices ... now think about it, do Europeans assign value to that?
The vast majority of cities do not even remotely look like some of the elite and lucky European cities that are built on the many advantages they got from (not looking for a flamewar here) but exploiting other nations (the behavior is in the past, but the advantages remain and accumulate), all I am saying is that it cannot be a model for <insert eastern european city here>.
If anything the clean, quiet, well kept European city is non-sustainable and non-replicate-able as a global model. We need to fix the problems of the suburbs but not by imposing a model that cannot work.
The global city model is a far less livable.
For most people, the ideal life is having your yard and be able to drive everywhere with enough lanes on the street to be sure you never hit traffic. Except that ideal situation rarely exists, all the roads are clogged (induced demand!) and having a large house for every person means a big desirable city to work can't scale. Even LA has understood they couldn't keep building highways and needed to densify, it just doesn't scale.