And why on earth not? So long as your device is as fully up to date as it can be, you're not likely to be at any more risk than using your own wifi.
If you're using something still on Android 4 or earlier, then maybe...
Exactly. Before I retired the company I worked for had a very rural base. We used to employ a large seasonal workforce some of whom lived on site. I came in one Monday to find all our monthly broadband allowance had been used - this never happened. Turned out a couple of the Polish lads living on site had been downloading films all weekend.
If someone wants to hack they will. I never do anything with my phone outside the house which needs to be secure. Why would I do banking in a cafe or pub? Using the same example my main bank account requires both laptop and phone present to carry out transactions, my second account requires laptop or phone plus a card reader. Who would bother to carry all this stuff around?
Online security for the individual is commonsense not something to panic over.