It's insane, isn't it?
We made some choices early on so as not to participate in this merry-go-round. First of all, our son was not allowed to be in endless scheduled activities at an early age. Yes, that meant going up against people who had their calendars color-coded so they knew which kid had to be where, when. We lived in a neighborhood with a lot of kids, so most of the kids were available at least some of the days to just run around, ride bikes, play frisbee and shoot hoops in the driveway. Our son did one scheduled activity (he chose sports but it could easily have been drama or crafts) and we did that through a town recreation program for minimal money. Another day he had religious school. That was it.
When he got to middle school, he did a little casual cross country program for no fee - they just stayed after school, ran a little, and maybe had one "meet" with another school just to practice sportsmanship and dealing with a starter's gun. In high school, he ambled over to the track team, which never cut anyone - a great program! There was a $175 fee for the year for any activities (sports, school plays, musical groups, social action club, etc.) and that was to pay the advisors (but many volunteered). There was a family cap of $350, and there was financial assistance available.
Some of the elite athletes did participate in travel teams through middle and high school, and I'm sure there were fees associated with that. And of course there were kids who did dance and gymnastics, some of whom were clearly driven and gifted - one kid is dancing on Broadway, for example. We just never saw the need for all of this, and our son never had that level of passion and talent to require something really extraordinary in either finances, time or training.
There are Olympic athletes, for example, who choose to leave their families to live with or near a nationally-ranked coach - but really, they are so few and far between, and I think you kind of know if your kid is in that category. But then that's where your money goes - they are going to the Olympics and not to college at 18.
We thought we'd give our child a less stressful childhood and help him find his own path. We didn't pay for outlandish sports fees (and we had good sports and music programs in the schools), we didn't put him in SAT prep classes or lots of AP classes or extra math classes from outside vendors. If he needed work, he stayed after school to meet with the teacher. If the school offered a one-day SAT practice class, he took it. (Okay, he took driver's ed, but that was for other reasons.) Otherwise, he had a social life and he made friends who didn't do everything at a super cost.
Meanwhile, our friends went broke paying for ice time and hockey equipment, dance lessons and recitals and costumes, and so on. The parents spent endless hours organizing, driving, sitting and waiting for performance times, and writing checks. We went on vacation, had kids over in the back yard or in the basement, and had small birthday parties in the yard or with 3 kids at the movies (no parties of 30 with bounce houses and party venues). We also didn't go to 35 birthday parties a year (with the cost of presents) because we didn't do whole-team or whole-class events. As he became a top runner, we did invest in good running shoes, but the local running store gave a 10% discount to everyone on the school teams. But he wore old shorts and hand-me-down jerseys if we had access to them.
Our kid is not a genius but he got into a great college with great financial aid, he ran track & cross country for 4 years. He found the ACT was his test and not the SAT, but not because of the classes he didn't sit through. He only took one AP class in high school, and that was senior year, and it was his choice. He's got a strong work ethic because his chosen activity (track) was a "work against yourself and the stopwatch" sport, not a big money maker from ticket sales. He didn't perform for a huge crowd of spectators but he learned team spirit and hard work. He took a lot of engineering classes with kids who had no social life because all they did was study. He got Bs and Cs and a few As, he got 3 internships and a great job. So I wouldn't do it any differently.
If you're not happy with the way things are, you can change it. Don't let anyone tell you your kids won't succeed or get into college without a long resume. Our kid had a home business of walking dogs, mowing lawns, spreading bark mulch, and taking care of homes when people were away (trash, mail, feeding cats/fish/gerbils, emptying dehumidifiers, whatever needed doing. He had a 6-year business to put on his college activity resume, he learned to work with a lot of different people, and got lots of references.
He had Hebrew school and a normal bar mitzvah that was about the rite of passage into adulthood and not the size of the party. He designed a social action project that would knock your socks off - so he was part of the outside world but more for giving and living those values the school was teaching. We just didn't spend on that party stuff. He survived. He flourished.
So don't be afraid to get off the hamster wheel and make your kids choose what's most important. That actually prepares them much better for college and for life, where they will have to schedule their own time, come up with their own fees, and make their own choices.