Some cafes have the shitty practice of imposing a captive portal for Internet access. Sometimes they demand personal information, and sometimes the captive portal discriminates against people with older phones.
Currently these cafes have the field “Internet access: customers”. That’s misleading and unjustly described. Some of them should be tagged with “Internet access: only for customers with new phones”. It’s not really fair to say it’s for all customers when they use exclusive technology.
Check the OP. it’s about login portals.
Indeed GSM is irrelevant because GSM towers cannot relate to any particular business. GSM standards are much less of a problem. When the country decides to abandon LTE, all non-5G phone owners are fucked nationwide.
It’s a Wi-Fi problem. Captive portals are the biggest problem, and the most obnoxious problem because it’s an artificially created problem as a consequence of incompetence. I only had captive portals in mind when writing the OP, but there are also situations where someone configures an AP to not use 802.11b (for example) and then old hardware does not even see the SSID. My laptop cannot connect at some public libraries for this reason. Then WPA versions /could/ be an issue, I think, but I have not encountered that.