Yes rubbish is a problem in Britain. If anything the older generation of Brits are the worse.
A lot have the attitude well someone is employed to clear it up some even go further if I did not throw it down I would be putting someone out of a job - I kid you not that was a thought at one time - less now but a lot of people of my dad’s generation had thought.
Ah that explains it. England and the USA were very similar in some ways yet complete different.
You probably have even more Subway sub stores then we do! I made it a point of staying away from any “American” food. That is one thing I really regret is how American “fast food” shows up EVERYWHERE now days
Of course I was there in April and only got rained on my last day so I probably have an abnormal view of England! ;-)