Is the premise of 15-minute cities really that every final destination is walkable within 15 minutes or that you can reach everything you need within 15 minutes?

If I live in a big city with good public transport and have most daily need things walkable within 15 minutes and good public transport connections also within 15 minutes then I can benefit from opportunities that are farther away while also having the locality of the rest of the day to day things.

That's what I personally would consider a 15-minute city

Yeah, I don't understand why this person makes it sound like a 15-minute city is some sort of a jail, or an island you can't get in a car and drive out of should a need arise...