Idk why would one bother to connect to a Wifi network everytime one enters a metro when nearly everyone has ample LTE data coverage. And to use wifi, one has to turn on the wifi and connect to the right network (2-3 clicks), agree to some sort of user agreement (10 secs wait time and another click), then get connected - altogether a multi-step process. It may be fine for the one off tourists who don't have local data coverage, but not ideal for daily usage and altogether a bad user experience. Especially with the upcoming 5G network upgrades, cell data coverage should become universal and we should expect data rates to decrease across the board for end users. It's 2020 not 1995, there should be no excuses.
On the plus side, not having data coverage on TTC always made for a tranquil (screen-less) ride which allows many to disconnect and read a book or do something other than browsing their phones. I remember many of my colleagues using "no data on TTC subway" as an excuse to not get on a conference call or answering their emails promptly