Crap conditions, compromising their registration, bullying, harassment, chronic understaffing, having leave cancelled at the drop of a hat, having to pay insane exam fees, salaries that would be far higher than they are if successive governments hadn't shafted them since 2010 in particular...
Don't believe me? Take a trip to any A and E, especially in the north west of England, and just observe the conditions for ten minutes. Try not to get in the way. If you want the full NHS tourism experience, do it on a Thursday or Friday night before a bank holiday.
You'll mostly (with the exception of a couple of A and Es in Greater Manchester which are generally akin to field hospitals but nowhere near as well organised) see stressed people doing their best with, metaphorically, elastic bands and tissue paper. That level of stress, day in, day out, is not sustainable for anyone. Add that to the lousy weather and rubbish general standard of living and it's amazing we've got any doctors left.
In other parts of the country it's almost as bad but there may be other factors that keep people going - beautiful landscapes or low costs of housing.
Oh, and Health Education England no longer exists as a separate entity, it's been absorbed into NHS England for a while now. Growing our own is a great idea but at some Trusts what exactly happens to at least some of the training money given by HEE has always been something of a mystery, as it certainly doesn't appear to reach medical or nursing or AHP education in any form. Under whoever forms a new government it would be helpful if NHSE could maybe start auditing where that funding actually goes and examining the financial evidence rather more carefully than they currently appear to...
In general for a bit of context around how recent governments have funded the NHS, try this link
https://www.health.org.uk/publications/long-reads/health-care-funding
For those blaming PAs anecdotally quite a few who would like to work in hospital settings can't get jobs as there aren't even any to apply for. There's a handful of GP based roles. At this rate they'll be emigrating too and we'll continue to charge insane visa amounts for overseas trained doctors to come and work here. That's assuming their qualifications are deemed acceptable of course, at least a couple of our friends from the Commonwealth with fantastic experience and qualifications had to redo their entire medical training. And this was an ex colony if you'll pardon the expression with English as the main language...