I think it is better not to use wifi in public places because your privacy is not maintained there most of the time. There are many places where if you connect to wifi they steal your personal data. And they try to use them later. So I think that it is better not to use wifi in public places.
I agree, it's better not to use them at all even you're going to use a VPN, I wouldn't dare to do that even if I've got a paid subscription with any of them or with the most trusted one.
Normal people do not share seed phrases and private keys online, with or without free WiFi. I am currently in a hotel on public WiFi. My private keys are not leaving my laptop.
We are normal people but you'll never know how a newbie can do such. Leaving their keys on their laptops and available on their desktop interface with a note on it as their "private key".
You'll never believe what a newbie can do because I've been there and done that.