I'm not making any value judgment on the various responses by local/county/state actors, I'm just pointing out that THOSE are the appropriate levels of government to consider, when discussing the length of time any particular group of students stayed out of full in-person schooling. THOSE were the people making the decisions. Not the president, not the CDC, not Congress. I'm keeping all of my commentary strictly within the context of this thread, which is "Kids' happiness" and not other issues related to the pandemic and any entities' responses to it.
In Leander ISD, my kids were only out from mid-March 2020 thru mid-September 2020. It wasn't two years, it wasn't 18 months, it wasn't even one year, it was only 6 months.
However, that 6 months made an incredible impact to my then-6th-grade daughter. I saw her turn from a bright, cheerful, outgoing, deeply happy child who excelled in all of her classes and never once thought about NOT turning in an assignment on time, into a withdrawn, timid, introverted, morose, ghost of a teenager who lost track of all sense of responsibility and normalcy. It took her almost two years to re-form good school habits and re-engage with her friends. She's now thriving, a straight A+ student with tons of friends and tons of activities, but even those 6 months set her back potentially years.
So people who are debating the 6 months versus 2 years or whatever, are completely missing the point. It's much less amount the DURATION of the event and more about the total psychological trauma induced by the event itself.