There is nothing wrong with using public networks. It's not 2010 anymore. Your operating system is expected to be fully secure[1] even when malicious actors are present in your local network.

[1] except availability, we still can't get it right in setups used by regular people.

You don't use public networks?

And when you connect to a non-public WiFi for the first time - how do you make sure it is the WiFi you think it is and not some dude who spun up a hotspot on their laptop?

Hmm. Are you sure that your stack wouldn't accept these discovery packets until after you've successfully authenticated (which is what those chains are for) ?

Take eduroam, which is presumably the world's largest federated WiFi network. A random 20 year old studying Geology at Uni in Sydney, Australia will have eduroam configured on their devices, because duh, that's how WiFi works. But, that also works in Cambridge, England, or Paris, France or New York, USA or basically anywhere their peers would be because common sense - why not have a single network?

But this means their device actively tries to connect to anything named "eduroam". Yes it is expecting to eventually connect to Sydney to authenticate, but meanwhile how sure are you that it ignores everything it gets from the network even these low-level discovery packets?