Here are some of my observations from the trenches (currently I teach in an urban private school, I have taught in the suburbs, and my kids attend a suburban public district):
1) Most teachers are perfectly fine using the technology. Before this happened, we were all using learning management systems along the lines of what universities use. So communication of assignments / grades / etc. was not a problem. Zoom raised some issues because of the "meeting crashers" but once we all turned on the waiting room feature (and once Zoom stopped using 32-bit integers as meeting IDs) that went away. Many of us had even recorded videos and done basic editing because we've occasionally done "flipped classroom" instruction, where the students watch the lecture at home and then work on the problem sets in class (I teach math and CS). A lot of teachers took educational technology like document cameras (or in my case, a Surface with pen) home so that they could have something equivalent to a whiteboard.
2) Special education students are probably the biggest victims of this situation. We did not have enough time to figure out how to address their needs. I know that in my own school, there's a lot of professional development going on this summer to talk about what we can do better if this happens again.
3) Assessment was a big issue. Take home assessments do not work well at the high school level. They barely work at the college level. I took a graduate course in mathematics last fall and the professor gave take home exams. She was reaming us out because people were posting problems on places like Chegg. We did not have enough time to figure out a good way of assessment. If we do this again in the fall, it's likely to be a blended model (meaning we would have some in-person days). Most of us plan on doing assessments only when we have the kids in the room with us.
4) Students' situations were all over the place. My own kids were high performing before, and were still high performing. Some students improved because they had more time to do their school work; other students were emotionally wounded by the whole scenario. Some students stopped doing work because they thought they could get away with it. I have some high performing advisees who choked at the beginning and then pulled themselves together after a few weeks (with their parents' help). Some kids were given too much work, but more were not given enough. My son was not getting enough work, so my wife and I supplemented with extra writing assignments and math contest problems. By the way, I recommend Noetic Learning for math contest problems if your kid is entering grade 7 or below. There's a fee, but the problems are well written.
5) This was hard on everyone: students, parents, and teachers. We learned a lot. Like just about every problem in American education, it usually comes down to societal issues -- segregation, poverty, parental educational backgrounds, access to internet connectivity. I'm taking a graduate seminar in computing this summer and this week we're talking about attempts to improve broadband access through satellite constellations and 5G. Rural counties in particular suffered here.