In most cases this really isn’t a problem though. The fantasy of “big tall buildings” being slapped everywhere is just that. NIMBYs are fully mobilized just to stop stuff like duplexes, townhomes, or the neighbor putting a pop-up 4th story on their existing row house, not imaginary 100-story skyscrapers going up in the middle of a suburb.
Getting rid of the idea of owning the neighbors airspace entails figuring out how to fairly allocate easements that generally don't currently exist because of legacy reasons.
Rule: you can't build more than one story higher than your neighbors.
Under this rule your property will become more valuable when your neighbor builds up, because it just got upzoned for free!
Developers a profit motived and are very aware of what sells and what doesn't. There are a million mechanisms by which we can avoid having a single story house surrounded by skyscrapers.
I used to be in favour of laxer planning regulations until I moved to Melbourne. A lassez faire approach just doesn’t work.
The problem with this kind of thinking is that the denser housing is, the more its livability relies on things outside of the homeowners' direct ownership and control. So long as YIMBYs keep pushing this idea that keeping access to things like sunlight cannot be a shared act, it doesn't matter how many pretty drawings of wide sunlit boulevards of townhouses or towers in parks they produce to claim that density doesn't have to mean dark, dystopian hellscape - because the moment there's money in it, someone can just slap a big tall building right in one of those crucial empty spaces, and according to the YIMBYs the people affected would have no right to complain because they didn't personally and individually own them.