The problem is there is no one size fits all nor is there a playbook, whether 10 yrs. old or 18 yrs. old. Some kids thrive playing tournaments every week, others like my daughter play less tournaments (12-15 yearly), a lot of practice matches (6-8 per month) and adhere more to a periodization approach to tennis (just like elite runners) . . . space out the tournaments, train to peak at the next upcoming tournament, then back off, recoup physically and mentally, and then get back to it.
But, our approach, was developed from understanding our daughter (how she ticks, what works for her, what makes her smile, what makes her love the sport, how her brain works, how she receives information, etc.), and this type of evaluation can generally only be done by the parents/relatives or maybe a coach if it's a coach that truly knows the kid, travels with the kid, and is in the trenches but that's generally the parents.
It's an incredibly delicate balancing act . . . week after week, month after month, year and year . . .