Topological
Established Member
Being an Economist by training, I book advance tickets on trains which leave Paddington about 2 to 3 hours after scheduled landing at Heathrow. Normally, I will end up with a long wait. If routing via Reading and the Elizabeth Line then I go for 2 hours 30 to the Reading departure time. There is less to do on Reading station than around Paddington.Given that inbound aircraft are completely unreliable for when they turn up at Heathrow, along with not knowing how long it takes for the bags to be delivered etc, reservations for those continuing onwards to the West Country are quite impractical, especially for destinations served multiple times an hour. You just want to get on the next one.
I suspect that people who needed flexibility would have a train in mind, reserve on that, then travel earlier if their plane was on time.
Advance tickets are fixed train only, so makes no real difference if there are people on from Paddington or not, you have to commit to a train.