If we’re making distinctions, we shouldn’t lump UK football and US soccer together either—facetious comment aside.
That said, I don’t disagree with your point, but your comment actually brings this discussion full circle to my original argument: U8 games don’t need a qualified referee.
When a club or league chooses to appoint a qualified official, they should expect the match to be officiated according to the Laws of the Game. If little Jonny commits a reckless foul, then little Jonny should receive a yellow card. The problem arises when a qualified referee is put in a situation where yellow cards aren’t "expected."
As far as I’m aware, the LOTG are not flexible on the definitions of recklessness, violent conduct, or serious foul play. Whilst interpretation can be subjective, if a referee witnesses reckless play, VC, or SFP, they must issue the appropriate punishment—whether the player is 7 or 70 years old.
And this, again, brings the discussion full circle. Referees shouldn’t be appointed to U8, U9, U10, or U11 games just for "crowd management," as it’s often a losing battle. In many cases, cards aren’t expected, and abuse towards officials is tolerated far too readily.