There are also super competitive clubs, but huge amount of them is not like that. My own kids go to clubs like that, my friends kid go to clubs like that. The teacher typically acts seriously and attempts to teach you what is possible during that time.
But scouting is whole another level, occupying afternooms, weekends and plus giving "homework" projects. The kids were either fully into it or left.
Pretty much everything else can be done at summer camp (1 week a summer) or maybe a merit badge fair on a Saturday once a year.
Sure, you might have to keep a log for a month of your chores, or do a home improvement project for the Family Life merit badge, but it never felt like a time sink as a kid, and didn't occupy all my afternoons. I essentially never had "homework" from Scouts.
Maybe some troops are really gung-ho, but there are plenty of troops that aren't. Troops are not allowed to set requirements that aren't in the Scout Handbook, if they are, there's the district, the council, and ultimately the national office that can put a stop to it or revoke the unit's charter.