So many things wrong with your post. Talk about out of touch with reality. Ill just deal with the main points.
"far too fragile for life, "
Or rather - they're not about to put up with your bullshit, and have enough of a backbone to act accordingly, rather than be so cowed that they never speak up.
see also: feminism, civil rights, gay rights, rewinding...Sufragette movement, abolition of slavery, rewinding... no taxation without representation, rewinding... The magna carta existed because a bunch of lords were no longer going to put up with the King's bullshit.
In a more modern context: Unwanted sexual touching is sexual assault. Slapping someone on the ass is a) often unwanted b) usually sexual in nature. Therefore anyone who does that where it was not consented to, has committed sexual assault. Spelling it out like this often annoys certain people, their thought pattern seems to go like this:
People who do sexual assault are obviously Bad People, and *they* are not Bad People, therefore, what they do *cannot* be sexual assault. If the victims make a fuss, they are accused of being "too sensitive" or "fragile". Its like the folk who think they are good drivers because they keep taking risks and haven't been in accident (having caused plenty).
"demanded salaries way in excess of their actual abilities"
its called market forces. The managers didn't have to say yes to those demands, but they did. Why? If the managers don't see your worth relative to the yunguns in the same way as you do, some of that blame lies with you. You can be secure in the knowledge that you are right as you apply for a dwindling number of higher level jobs. Hope you kept those skills up-to-date.
"By their own choice"
Gentrification is what happens *after* these young folk who *go on* to become professionals move in. Until then, its the cheapest place to live, crime rates are high as no-one has anything. Think Brixton or Queens from 10-20 years ago. The trendy coffee/wine bars spring up because its where their market *is*, not the other way round. Leafy suburbs are for rich people.
"So they have their own little community already then."
Spoken as someone who has obviously never lived in a house share.
"...hospitality do have a lot of young staff and are down the swanny, but that's a small proportion of the young."
No. it really isnt.
Young folk are more likely to be in hospitality or retail than any other industry.
"you can't be furloughed from not having a job"
A few that might have been true during the age of "The young ones" ~40 years ago. Show me a student that doesn't have a job today, and I'll show you someone who is being bankrolled by their parents. Maybe that's more common in the US, but over here, part of the leaving-home-for-uni right of passage includes financial independence. Unless, of course, your parents are absolutely loaded, but most folks just aren't that rich.
In conclusion, your worldview seems to be of someone who doesn't think the world has changed in the last 30 years. It has. With Millennials now pushing 40, it's not just "young people" with these newfangled viewpoints. Society is always changing. Keep up or get left behind.