I bought an LG G7 from Google Fi, and it was exactly 18 months from the phone's release to when they stopped updating it. I didn't buy it on day one either, so I got even less. I vowed that was the last e-waste phone I'm buying and moved to an iPhone last year.
There are still a lot of things I like better on Android, but it's not worth it.
This is in large part due to poor luck and changing phones a lot, but I managed to use Android for around 4 years without ever receiving an over the air system update.
There are still a lot of things I like better on Android, but it's not worth it.