In the UK at least, there has been a huge exodus from academia, but it’s not really visible. Great post docs rarely stay, because either they’re enticed elsewhere by better wages and no nonsense, or they’re pushed out by awful treatment.
But there are plenty of other people willing to take their place, so the only consequence is that research standards drop, which is something most of society will only notice over the very long term.
So I disagree with the idea that individuals leaving will somehow fix the problem. The real solution is to change the terrible culture imposed on academic by the people at the very top. Turning it into a business espousing KPI driven nonsense rather than a vocation. This culture began in the USA and is now widespread in the UK, and it has destroyed goodwill and IMO resulted in dramatic drops in teaching and research standards.
The solution is to scrap REF, restore direct government funding, rebalance funding from grants to departmental funds, reverse the centralisation of administration and the lop-sided admin-academic balance, remove admin workload from academics, provide proper teaching and research career tracks, and cut the number of students attending university.
This is a problem that can only be solved with intelligent thought at the top, not by people acting individually. Market forces are the problem in academia, not the solution.