They've never really been reliable anywhere. I have the same issues with the streetcar being "4 minutes away" and then 4 minutes later it's "3 minutes away."
With streetcars it's a little more acceptable (cars turning in the way; a lineup delaying a dwell, etc.).
With the subway, I've always assumed weird time changes where when vehicles were taken out/put into service. I've sat there at St. Clair and watched the time regularly flip between 4-9 minutes for the next train. The 9 minutes ended up being the correct time.
But it's not even limited to the TTC, I had a grocery delivery from Metro yesterday and it said the driver was 5 minutes away on the tracker, but it showed his van was at Bathurst and Lake Shore. I'm a Queen and Parliament, so yeah, no way you are making that trip in 5 minutes ever, but especially at 7:00 p.m. on a Saturday night. Uber is the same. "Driver arriving in 1 minute" usually means 5 minutes.
I get delivery from both Metro and Voila. Voila is spot-on for hitting within the delivery window, and their more precise predictions (visible on the order information when delivery vehicles hit the road) have never been more than a few minutes off.
Metro on the other hand can be a sh!tshow. If they didn't have products I can only get from them, I probably wouldn't use them at all. Several times over the past five years they just haven't shown up for a delivery (at all), with zero notice. I have had to be the one to track down as to why, often calling an hour or more after their expected delivery. Their predictions are ridiculously bad, and they often fall outside the window on the times they do show up, otherwise I'd be calling 10 minutes after they fail to show.
I've been told the problem there lies with the individual Metro stores. They're the ones who deal with picking and deliveries, despite it being a centralized ordering system.
Metro used to be better though. When they first launched delivery they were absolutely awesome. They've become more and more reliant on partnerships with 3rd party delivery (Uber Eats, etc.) even if the customer isn't aware of it. A lot of the downtown core is specifically handled by the Metro Stockyards location. Metro completely ignored user settings for "my store" (now removed from the website) and ships from a handful of larger stores. And again, the problem lies with those stores. They own the delivery vehicles that break down (and their lousy maintenance). They're not super keen on having to deal with the level of delivery they've gotten since the pandemic.
After going up the chain with Metro's HQ, I was assured that they have a new system in the works that will be far more reliable. I'm assuming it'll be deliveries straight from their Etobicoke distribution centre, more along the lines of what Voila does.
Side note; join two different delivery services subscription plan as I have and compare prices. In doing so I can *always* find enough savings between the two to pay for the cost of both services. As a result I get better selection, which is acceptable, even with Metro's frequent cockups.
I'm convinced there is some kind of systemic issue in the prediction tech that all these services use, which likely is not their own but sub-contracted to various software firms with really poor prediction algorithms, though the cynic in me says they all play with the time a bit to make sure you are early and not late. They want you to think you only have 1 minute when you indeed have 5 so that you are ready for them.
I don't think it's completely intentional, I think the algorithms are just tuned to be optimistic. I'll liken it to Apple Maps versus Google Maps. Google will always show you a faster trip, but Apple's is almost always more reliable and correct.
