I think the success of distance learning really hinges on the individual child. You can certainly help with having the right conditions, but that's not sufficient. Echoing some of the PP, we are fortunate that we could make sure each DD had their own device, a private space to study/meet on-line, and the fastest internet speed we could get (since we often had 3 Zoom/Google Meet calls at once!). Their school had mandatory live classes every day while I was working full-time from home with multiple Zoom meetings per day.
I was also surprised that the middle school continued to evaluate using regular letter grades. Most other public schools nearby switched to pass/fail instead. This meant my 8th grader was expected to meet all the regular expectations and do it virtually. I thought it was unreasonable as I imagine many students struggled with the virtual learning environment. The teachers tried to maintain regular daily classes, but they mostly sent assignments by email and then offered live science and math lessons. There was also a daily "morning check-in" class that was just 15 minutes to take roll and then the teacher (an 8th grade teacher!) would read a chapter aloud. I know this because I did not insist DD1 wake up by 8 am to do that. I'd log in for her, keep the camera off, and then log off when the teacher finished reading. I usually don't "break rules" but I know DD1 needs her sleep. She still graduated with all A's so she put in the work needed.
For DD2, a 5th grader, they had occasional class meetings, but it wasn't every morning like my 8th grader. She had to submit "tickets" once she completed the work to show her teacher she finished the assignment. I was working full-time so I didn't have time to monitor how that process worked. Fortunately, both of my kids adjusted well to independent learning with very little supervision from me or DH. The key was having their own devices and designated space. Plus both are diligent and conscientious so we're fortunate that they're naturally inclined to work well independently.
The biggest issue is that they really missed their friends. So we relaxed our screentime rules and let them Facetime/Google Meet friends or play Fortnite/Minecraft online with their friends. We have had WAY too much screen time since the shelter-in-place orders began in March but this was a survival tactic. If we go back into distance learning, I assume we will continue the unrestricted screen time so they can interact with friends.
We did host an outdoor playdate for each DD, with everyone masked and 6 feet apart. The hardest part is making sure they remember to stay 6 feet apart. DD2 and her friend basically played on their devices and talked to each other 6 feet apart. DD1 and her friend took photos of one another and talked a lot. DH or I occasionally went outside to make sure they were keeping their masks on and maintaining their distance. Thankfully all of them did a good job of being strict. We know it's risky, but emotional health is important, too.