You might like this: https://docs.vizycam.com/doku.php?id=wiki:birdfeeder_app

Not sure this will work but for our birdseed we've had good luck with that super hot pepper oil. Less than a teaspoon of it in a (1/2 gallon?) sized container of birdseed, shaken for 30s-1m to get it distributed has kept the squirrels and raccoons off of it. Couple times and they don't even bother.

Doesn't bother the birds, but mammal tongues light right up.

I can't currently link to it but this reminded me of that Mark Rober series of videos about squirrels.

Could one invest in hawks, owls or snakes?

Hawks and owls require multi-year effort in Falconry licensing (at least in the US).

First 2 years under a sponsor--you can get a very specific hawk or falcon (which hawk or falcon is geographically dependent) After 2 years & sponsor approving it-- you are now a general falconer. Have fun with other raptors, including owls. OTOH.... Wild Owls: excellent pest control.

Squirrels are just tree rats. They'll eat anything. I'm more sueprised that nets are effective than their choice of food.