Living in a growing city is much better than living in a dying city. Ask Detroit or the hundreds of them in middle America. They'd swap in a hot minute.
If they're arriving in a city that's already unbearably expensive, and it up doing normal life things (coupling, planning for kids), they might end up leaving back to either that Rust Belt city, that might have a 'revitalized' downtown (microbrewery, craft coffee shop, pricey ice cream place) or two one of the burgeoning smaller cities that has better amenities than the Rust Belt one (Portland, Austin).
Then there are forgotten cities, that have good employment and affordable housing, but aren't as sexy such as Minneapolis, Raleigh-Durham, maybe even Chicago.
I'm currently in LA and the exodus is real. It sucks for people that grew up here since the wages aren't great in most jobs, housing is out of reach, and they want to be around their family.
Will the last person to leave Seattle please turn out the lights?
Seattle has been dying before, particularly when it was more dependent on Boeing who would go bust every 10 or so years. Seattle will probably die and be reborn again.
Living in a growing city is much better than living in a dying city. Ask Detroit or the hundreds of them in middle America. They'd swap in a hot minute.