You have to see the bigger picture about vaccinating as many as possible as quickly as possible, and not just what's most convenient for you.
Most people first get offered the jab via the national booking system. They get a letter or they can see their age group is eligible in the website. That takes them to vaccines at the mass centres. For some it will mean a bit of a journey. But these centres have huge capacity and it's the way to get through the vast numbers. The quickest way to vaccinate the population is for everyone who gets that invite to book as soon as possible and take the first appointments.
The GP led system is a different system. It was used early on for the elderly and then for the clinically vulnerable groups and for the vulnerable group 6 people. Centres tend to be local to where people live, which was considered important for elderly and vulnerable. GP led services also picked up people who didn't book via the national system....and people were free to wait for this, but it does slow the system down as it delays rollout to next groups. Some people had no way to get to the mass centres and that's why the option was provided, but some coukd have gone or booked on the national system sooner and just didn't. They wanted convenience or to walk for their jab. I think many people really only thought about in terms of themselves and not about the national rollout and what would enable most people to get it fastest. As we move down the age groups, more and more people of course can travel. It might invoke a bit of planning for some and not be an handy as nipping to the local centre, but more people can be done faster if people will do that. There are also lots of volunteer services which will take people for their jab if needed.
In the end, everyone should get the jab within a couple of weeks regardless of which system they use. But if people want it fast (and most say they do, but then their actions often don't support that) they should book as soon as they get invited, whichever system asks them first.
Speed isn't key for lots of people, they'd rather wait and not travel. Well that is their choice and the system recognises that and allows for it. In most cases it means the individual will be jabbed later and also that others will be too.