Regarding Brexit.
Lots of young people in the so-called 'Red Wall' areas voted for Brexit.
But of course that's just looking at generalisations. Not every older person, or everyone in the Red Wall, voted that way.
Also, it was the older generations in the UK who voted to go in to what was then the EC. So if it wasn't for the older generation , the UK wouldn't have been in what became the EU in the first place.
Also although not 'boomers', I understand that, if you want to generalise, the 'silent generation' (the one before 'boomers') statistically more voted to Remain than Leave. DH's parents are that generation and they both voted Remain. (In the original referendum in the 70s, one voted to join, one voted against).
On a related note regarding age groups. In the recent EU elections lots of young people voted for Eurosceptic parties.
Really though, every group (age, region, or whatever else) is varied, and it's ridiculous to lump them all in together.
Also it's very unhelpful to condemn people for their voting choices. If you don't like the way they voted, look at why they did and address their concerns instead of saying "you're Bad". That's relevant for any election.