I think what you're looking for is a more rural existence.
Speaking for myself, absolutely not. The amount of things available in cities compared to rural areas is immense. I’ve lived in both.
Theater, music venues, libraries, restaurants, beer gardens, good food markets, schools. I have all of this writhing walking and biking distance. You don’t get that in rural areas without needing a car.
They SHOULD be better but... no.
Then again my urban experience is Minneapolis St Paul, possibly the most bike-able city outside of winter I've seen.
It's certainly not as bleak as you describe.
as for alternative roads, that really depends. generally from my experience between two neighboring villages there tends to be only one road, unless you want to make a big detour. sometimes alternate roads exist when and old main road is replaced with a new one on a different route.
The point is if there was a dedicated (about a metre wide, cut off from road traffic by a raised kerb) cycle lane not just through Londons busiest roads but ... well everywhere there is a car road.
Just say if you want a car there you should also have a bicycle.
We seem to think that the industrial revolution chnaged something - like globally there should be some kind of "profit".
I think it's just we as a species get to still be at a subsistence level, just a higher subsistence level.
NB- re london cycleways - yeah people do die. The cannon street path was opposite the LFB station and they did not have far to go to wash the blood away sadly.
Sort of agree, although an electric assist (for people who aren't in great shape, to get over hills) might be an exception. Limit it to 15mph or whatever.
It would be so nice to share most roads - but like op mentioned traveling through the historical European sites, the greenways being built here are approximating that. It is changing our city government significantly. Hope it is yours as well.
People tend to forget that while there are benefits in increasing density, they don't continue ad infinitum.