American football is known as simply football by every American I know. And I know, and have watched football with quite a few.
They would be Americans then. So neatly covered a point made later in the same post ….
It is only “soccer” where it is genuinely a smaller sport than other variations
As we aren’t American (in the UK) generally, we don’t have the need to differentiate like they do. As “Football” will do perfectly here, everyone knows what you mean.
You even used the term “American Football” yourself, which kind of illustrates the point wouldn’t you say?