I have two kids doing remote learning (one in kinder, one in 3rd grade). Since the 5yo is only on her 3rd day of remote learning ever, I'm spending more time "babysitting" her session. The class does involve some amount of physical movement (e.g "now go bring something square") and leaving the zoom meeting for 30 min periods to focus on drawing activities, but then I need to be on top of whether the kid is still engaged (or whether she wandered off to play with legos) and of what times the zoom class resumes. When you're dealing w/ a class of 20-30 small kids, there's a also good chunk of time wasted on logistics (fumbling w/ zoom password, waiting for kids to rejoin the meeting, "jimmy, you need to mute/unmute yourself", "please raise your hand if you want to talk" reminders, etc).
I feel that the class content seems sufficiently engaging (compared to my own kinder experience of strict butts-in-chair, all forward facing desks and a blackboard in a physical class), but even then, it requires dividing my attention between work and making sure the kid is on task.
The third grader has some experience with remote learning from before summer vacations, so things are relatively more smooth when the class is on, but we still need to keep tabs on when recess breaks are supposed to end. His teacher apparently has quite a bit more experience w/ remote learning from teaching classes during summer, and the class appears fairly engaging, with good usage of share screen and multimedia. But I do feel like the quality of learning seems low. Not sure if it's because of US standards. My son's curriculum hasn't really touched multiplication yet, but I distinctively remember having that mastered in 3rd grade, and also singapore math booklets that my wife bought to complement studies also apply both multiplication and division extensively at 3rd grade level)
It can also be challenging to juggle both parents AND both kids having zoom meetings simultaneously, since meetings are mutually disruptive, especially with loud multimedia activities. I feel like the parts that work the best are the ones similar to my old-school education: giving instructions on a task, then letting kids do them, recess, rinse and repeat. I'm not really sold on the high tech gimmicks (videos w/ songs etc).