Law is no longer a solid choice unless you're really at the top of your game and even then most people won't ever earn £200k.
Most firms now only recruit trainees via their internships. Most firms have reduced the number of trainees they are taking on since AI is changing the game significantly. DC with 4 A* and on track for a First has an internship place this year and had to make around 40 applications to get it. Each application takes around 5-6 hours which was then followed by many hours of critical thinking testing, situational judgment testing, online virtual interviews, assessment centres and in person interviews. They had over 2000 applications for their internship scheme and with the number of places on the scheme compared to the number of training contracts available, even at this stage he only has a 1 in 5 chance of getting a spot. If he had a training contract at this particular firm (international firm) he would earn c60k in a regional office once he qualifies (in four years' time) but would have to reach equity partner level to get to £200k which takes many years and isn't an automatic progression (London office would be different and attracts a premium).
This process isn't particular to the big firms. It's all firms. It is not the case that there are lots of jobs available at smaller lower paid firms which are much easier to get.
If you make it then great but the opportunities are really hard to come by. We are a family of lawyers and in my day, whilst it was tough to get a training contract, it truly was nothing like this. The universities are pumping out five times as many law graduates each year as there are jobs (and then you have the law conversion crowd which adds another c40% and also the graduates from previous years who are still trying to find a place) Nobody should be starting law school unless they already have a training contract lined up since only 40% of those going to law school manage to pass the new solicitors qualification exams, most won't have a job at the end of it and unless they have sponsorship they will end up massively in debt.
So yes, in law you can potentially earn £200k if you work very hard and have a lot of luck on your side but it is now extremely difficult to get a job in the first place and anyone saying otherwise is lying (or has out of date knowledge of the process and job market) I don't recommend it to anyone anymore and I think its sad that so many kids are sold a fairytale.