There is some truth to everything you have mentioned.
Taking the little devices from kids is a major issue.
At the moment, a lot of facilities of all kinds are closed which concentrates the use. We have more campgrounds, RV parks, and places to go than ever before. But the use and number of people has also increased.
Some National Forests are ramping up logging which is opening up the old road networks and adding a few new ones. Boondocking in a NF is the easiest way to replicate your childhood experiences for your kids. It is totally possible to do that in N California. I do it all the time. You must be more selective about where you go. July and August are the two busiest months by far. I now avoid most National Parks and CA State Parks because they are loved to death.
We have more acres of wilderness areas in the US that any time in history. Consider taking your kids on a short easy backpacking trip in good weather. That is the way to guarantee remoteness and lack of people.
Take them on some day hikes from your camping destinations.
Show them some western history. Take them out after dinner to look for wildlife at twilight. See if you can develop some interests in things like geology, wildflowers, fishing or whatever they like. Show them the night sky.
This no time to moan about missing the past. Go find what you are looking for.