Kids are wildly different and families have different situations and priorities. No point in feeling guilty or smug about how much you do or don't do, nor in judging others for doing 'too little' or 'too much'.
For us, as much as can be fit in is great so long as:
- it is lead by DC's interest/enjoyment
- DC is comfortably handling the cognitive and physical load
- we are willing and able to put in the time and money
- there is still quality time for free play, self-lead activities, family and schoolwork
Our 7yo only-DC has always done loads and most of DC's activities currently feel like play for them and they have made friends in, or brought friends into, many of them. As someone else said, now is the time to try things out and get to a basic level in a range of things before life gets busier and busier with more schoolwork, exam prep, self-lead social lives and summer jobs as they get older. And, of course, before they have to start committing to one or two things if they want to be competitive/part of a high performing team/get really good.
After the summer DC will be continuing: Fencing (after school), Beaver Scouts, Ballet (after school), Judo (club), Swimming (club), Gymnastics (recreational) (club), Piano (1 to 1 lesson at home) + daily practice at home, Hockey (club), Tennis (1 to 1) + 1 practice with family, Mandarin (online lesson at home + daily practice), Drawing (online lesson at home), Chess practice (at home, previously after school club)
and adding: Choir (before school), Music Technology (after school, instead of Chess club), maybe Cello (at school) + daily practice at home
Some (swimming, tennis, piano and Mandarin) are non-negotiable for us, though DC enjoys them also. The rest are DC's choice and DC does not want to prune anything more at this point, despite encouragement.
30 mins of homework a day, whole family breakfasts and dinners nearly every day, weekend afternoons are kept free for play-dates, birthday parties and family activities and outside these times, these can take priority over organised activities at DC's discretion. There is time, mornings and evenings and weekends, for free play and for DC to indulge passions for reading, drawing and crafting, and listening to songs about poo, as well as an occasional bit of TV. She can and does 'just be' with the best of them. There is plenty of time during endless school holidays for the same plus occasional activities like horse riding, snow sports and sailing (all of which we can enjoy as a family) and of course learning how to be bored/fill their own time.
We are at the extreme of what can work for us and some things would doubtless benefit from more time/focus. It only works because we have just the one energetic, enthusiastic, endlessly interested child, everything not at school or at home is available within a 10 min drive / 20 min cycle, and we are fortunate with reasonably flexible hours, working from home and (just about) enough disposable income and time.
She would definitely do fewer structured activities if we lived somewhere where she could safely and easily get together with friends and run wild and/or do activities like swimming and water-sports under DC's own steam and we would not be able to afford such a schedule for more than 1 child. We full expect focus to narrow over the next couple of years, and especially beyond as DC moves into Year 5.