I think there's a good amount of variety here. I often see Americans complaining about the quality of Mexican food not being great here. And that's probably fair compared to what you can get in the US. But that's because the UK doesn't have the same historical ties to Mexico as the US does. But, to give an example, because our history is more closely linked with India we've got a lot of fantastic Indian food and probably are better than the US when it comes to that based on what I've seen and speaking to Americans.
When it comes to our own food, it's probably fair to say we're not quite up there with top-tier culinary cultures like France or Italy. Our cuisine tends to be fairly simple but hearty, you can't go wrong with a good steak pie, for example. That said, we do have a few strong points in our favour. We're lucky to have access to excellent natural resources, particularly when it comes to beef and seafood.
Another advantage is that, since we're one of the "culinary superpowers," we don't tend to get too precious or pretentious about our food. Take Italy, for instance. In my experience, Italians often stick to mostly eating Italian food and very rigidly adhere to their traditional styles when making those, certain dishes must be prepared in very specific ways. While that kind of tradition certainly has its strengths, and their food is fantastic, it can also be a bit limiting to have that approach.
By contrast, British cuisine has shown a real openness to outside influences. To circle back to my point about Indian food, you can look at how curry has become a staple of the British diet. Our chefs will often train in classical French techniques, then return home and reinterpret our own traditional dishes and use our ingredients in ways people are more open to than they might be elsewhere.