People in countries like Switzerland with a high percentage of renters (58%) somehow manage to retire...
I would say a prerequisite for safe retirement is to have enough to buy a home outright in cash, otherwise mortgages will weigh you down like a stone:6% interest on a 1 million gbp loan in the UK is unpayable for majority of people even in London and yet you wont find anything worth buying there below that price.
Also we should stop saying a house has equity: it doesn't. You are a paying off a loan for a commodity. A house is like a car or groceries: necessary, yes, but not an investment, unless its luxury. This is how we exploded house prices.
Both of you say a mortgage is unacceptable.
Equity is simply the assets you hold. You can have equity in a car or groceries only it will disappear quickly if you don't sell the car or groceries.
It's not, but that's a level of passive income that most Americans can not achieve. I suspect it's also structurally impossible for everyone to get there, but yes some individuals can do it.