Its not effective because none of the schools were setup to use it at short notice. I have been teaching online classes for over 6 years and the technology is way more advanced then current schools were using since it was basically zoom meet ups. The thing is we have enough time to invest in those online tech to make remote classes almost as good as being in the classroom. I will say with my years of experience that the gold standard will always be in classroom teaching but we do have the tech to make remote a very viable and solid solution definitely during this time.
As for this children are damaged by not going to school, I highly doubt not going to school for half a year or better is suddenly going to damage your child. Kids are not porcelain dolls where they break so easily, if anything children learn to adapt far quicker and better than adults. You really cannot regulate kids to wear a mask for 8 hours a day, 5 days a week. Even if you could if the virus is airborne then it really only takes one child saturating the air sitting in spot for a long period of time to infect everyone. Those kids rotate from classroom to classroom and one child can effectively infect the majority of students. Parents send their child to school all the time sick. Some with mild symptoms some with more depending if they need to go to work. In poor neighborhoods it will be a blood bath as most of those schools are already pretty crowded in class size already.
Hopefully they can improve online schooling here since the back to school measures all look hopelessly ineffective. (Canada)
My kids have been home since March and it is definitely effecting them. Home schooling was a pita since no one was prepared and it consisted of the teacher emailing some badly scanned text book pages with a PDF file of things to do during the week while providing access to Lexia, Prodigy, IXL, Bright space and Zoom which all had their own issues and problems to use.
Zoom meetings were nothing more than "Can you see me" "Can you hear me" "A dropped out again" "Can't hear B" "Where did C go"
Uploading work was a nightmare, feedback was non existent, materials were obviously missing and you couldn't go to the store to get stuff. Plus all those programs had their own login issues. They were also a mix of too easy and stuff the kids didn't know yet which led to lots of frustration and tears (8 and 10 year old)
All it did was turn my kids 100% against online learning, which turned into open rebellion and giving up 2 weeks before the end of the school year. Not worth the fight every day. In fact nearly all kids dropped out, many far sooner.
Since we're building up to a second wave for September / October I have little faith in the new school year :(