Oh yeah that'll solve everything, just like it did in Uvalde, Parkland, and Littleton.
Dude in each of those cases there were lots of armed and armored men and they didn't do shit. Why? Because they were scared they were going to get shot to shit. Human nature and all.
Armed guards won't stop schools from becoming slaughterhouses. People commit mass murders in schools because they are soft targets, like music concerts, airports, and movie theaters. You'll never get the manpower you need to prevent school shootings. States and local communities have teacher shortages right now, so what makes you think they've got the resources to put armies of armed guards, roaming through the hallways like UN peacekeepers?
I agree there's something else going on besides just guns themselves. A lot of toxic social isolation and too much time on the internet and playing Playstation, no doubt. But guns - especially AR-15s and other military-type weapons - are a major factor and will continue to be until there is meaningful recognition of that fact and a desire to do something about it.