I am a non UK person who watches Premier League games. And since a few months now I even watch Italian League games. But it is the same for me supporting a local team and a foreign team,,, I support only the team and the players and coach and style. I am not a crazy fan hating others, I do not even know the birthday of my favorite players like Son!
I just like watching good football. But as a supporter, you also feel the "enjoyment" of your rivals not doing well. I do not think this is about where you are from. I believe in this thead 10% maximum of supporters are even from the same city as the club. I for sure never seen London,,, I do not even know where my club stadium is if you throw me in UK
In my case, I do not have rivals because I do not have teams that I support. I mean I love some players from city, love some from Liverpool, love some from united, so I can't just feel happy about one team being better because others are doing worse. So for me, it is all about watching good quality football.
I love watching premier league and la liga because if you ask me that is the two best leagues in the entire world and I do not think that we would ever get any better leagues for a while as well, they are just great. Watching Bayern is great too, I would love to see them lose championship just once to feel at ease to be fair
but watching them play is great, and watching PSG feels great too, but those are just one team, so I could be considered "fans" for them since other teams are not enjoyable.
Premier league is not like that, they have 10-12 teams that I love to watch, hell even Southampton, watford, leeds trio at the bottom is great to watch because 2 of them had crypto sponsorship and leeds had docuseries.