I wasn't as good as I wanted to be in enforcing chores, but I did not think my kids were overworked! It's more a societal thing that kids' time gets channeled to school plus fun stuff and expectation that adults do all the other work.
I agree it's ideal if you can brainstorm together on the idea that it's "citizenship" as well as learning activities needed to be a successful adult. These vary with age of child, so that older teen may be learning (and paying for) car maintenance, paying bills while younger kids simpler chores. Maybe certain kids prefer certain chores (not that they're "coddled", but again, finding ways to use talents and preferences.
And maybe it's hokey, but I always liked the idea of, if we all get the house cleaned up together, we can go for pizza and movie (or at home)--anyway, tying in how you work and you play, everyone gets to do that.
Since all families are different, it is indeed about balance. Does each family member have time for school, work, play, downtime, and the mundane and necessary chores? What is each family member's "bad day" or long day and can we all work around those?
Are there chores that are created by having too much stuff, too complicated systems? Cook once/eat twice; not thousands of toys to put away; 10 min pickup daily instead of monster clean up on the weekend. Different things like that.
One of the best reasons I ever noted for having kids do a reasonable amount of chores is that you like your kids more when they do, and you end up wanting to do more for them (maybe in other ways). It's quite true, it's very positive for relationships.