

Most of the more obvious ones are intended as travel food. Wrap something tasty, nutritious, or expensive in a semi disposable, edible wrapper. It’s a basic stable of most of mankind. England tended to use pastry or batter for this. Battered fish and burgers are other examples. Other as regions might use leaves for the same job.
If it was in a good state, you could eat it. If it wasn’t, then you could still eat the good bit inside. The crust of a Cornish pasty is intended to be thrown away. Coal miners could take them down the mine, and eat them without washing their hands.
Other dishes are a thing. They tended to be more family orientated however. The recipes wandered over time, with less stable traditional dishes. Bangers and mash, or a ploughman’s would fall into this sort of category.
Baked beans are definitely a VERY British thing, along with fry up in general.
Scotch eggs are Scottish in origin, I believe. I bundle them in with British, though a good chunk of Scotland would disagree. Definitely good, either way. Kippers and haggis are also Scottish/northern England traditionally.
As for Greggs… I personally consider them an example of how British food got screwed over by mass production. I’ve been disappointed most times I’ve brought from them. I know a lot of people swear by them however.
As for Yorkshire pudding. It’s a case of a good one is absolutely amazing, while an average one is just meh. It also needs a good gravy to dip it in. Hence why it goes so well with a roast.