It’s fairly common where I live, but dentists recommend against it because it weakens tour enamel.
I’ve never done it. Reasonably healthy teeth can be quite stained before they become noticeable to a random stranger while you’re talking of whatever.
A couple of ideas:
Home Ownership. I know condos exist, but it seems to me that we need a solution for home ownership that is accessible and ecologically viable. Traditional houses (and even duplex’s/townhomes) are massively inefficient from a climate perspective, not to mention the space requirements and cost.
Child rearing. In college, I learned that children were typically raised by multiple neighbors, in order to lessen the strain on parents. I think it is unrealistic and unhealthy to expect people to nearly kill themselves attempting to raise a child for the first couple of years.
Recreation space. I realize this is mostly an American thing, but lawns are a colossal waste of space. To be of any use at all, they have to be at least half an acre, and realistically, there’s no reason every single family needs their own outdoor recreation space. Plus, a tiny minority of people even use them these days.