People want to live in SFHs because cities are currently full of overpriced shoebox apartments with almost no options between that and car dependent suburban sprawl. It's not for me personally, but townhomes and other mid density developments are perfect for most families and far easier to serve with public transport (see: streetcar suburbs). You can still mix in detached single family housing in urban areas where demand is low enough to make the financials work too.

I don't quite understand the take about privacy. I lived in a house as part of family of 5 people, sometimes we got visits from another three relatives and they stayed overnight. The house provided more space than the apartment, sure, but it was nowhere near 'privacy', you can hear everything and everyone, the only advantage is that there's no drilling unless there is a renovation going on, and if someone shouts or listens to the music loud you can go and ask not to do that. Also, you can probably do that in the condo, so the problem with condo is really just the amount of renovations that will inevitably start here and there because of the amount of apartments.

I guess there is some middle ground where the building is comfortable even if you're not the only family living in it