I’m 38. I actually think it’s more likely we will have Medicare for all than Medicare gets shut down by the time I’m 65. Obviously, you need quite a swing of the political pendulum to get there. You’d need the Democratic Party to truly adopt the policy (which, I think they are going that direction), and then have them win the WH, House, and Senate. But, of course, it would be hard to do without 60 votes in the Senate. Unless they have a majority and change the rules, etc. But, if they got ACA done 10 years ago, I think they can get Medicare for all someday.
Not saying I necessarily WANT it to happen. I generally do, but I have reservations.
I don’t think SS or Medicare will ever be killed. Americans don’t want to watch old people die in the streets. Americans also don’t want to financially support their elderly parents, that’s for the taxpayers. I think worst case scenario they start seriously reducing the benefit payouts for SS (which would just incent recipients to move to LCOL areas even more) and/or use means testing for both SS and Medicare.