In the past I have found obstacles to data sharing codified in the UK law frustrating. I'm reasonably sure some people will have died because of this, that would not have died otherwise. If they could communicate with the NHS, similarly (email, whatsapp) to how they communicate in their private and professional lives.

Within the UK NHS and UK private hospital care, these are my personal experiences.

1) Can't email my GP to pass information back-and-forth. GP withholds their email contact, I can't email them e.g. pictures of scans, or lab work reports. In theory they should have those already on their side. In practice they rarely do. The exchange of information goes sms->web link->web form->submit - for one single turn. There will be multiple turns. Most people just give up.

2) MRI scan private hospital made me jump 10 hops before sending me link, so I can download my MRI scans videos and pictures. Most people would have given up. There were several forks in the process where in retrospect could have delayed data DL even more.

3) Blood tests scheduling can't tell me back that scheduled blood test for a date failed. Apparently it's between too much to impossible for them to have my email address on record, and email me back that the test was scheduled, or the scheduling failed. And that I should re-run the process.

4) I would like to volunteer my data to benefit R&D in the NHS. I'm a user of medicinal services. I'm cognisant that all those are helping, but the process of establishing them relied on people unknown to me sharing very sensitive personal information. If it wasn't for those unknown to me people, I would be way worse off. I'd like to do the same, and be able to tell UK NHS "here are, my lab works reports, 100 GB of my DNA paid for by myself, my medical histories - take them all in, use them as you please."

In all cases vague mutterings of "data protection... GDPR..." have been relayed back as "reasons". I take it's mostly B/S. Yes there are obstacles, but the staff could work around if they wanted to. However there is a kernel of truth - it's easier for them to not try to share, it's less work and less risk, so the laws are used as a cover leaf. (in the worst case - an alibi for laziness.)