Which I purchased in 2020, at a time when it was the newest model available.
Saying "2020 Surface Go" implies the 2020 model. Which yours isn't the model from 2020, it's the model from 2018.
Which is why it's a lot better to use the actual product names instead of just the year you purchased it. If I buy a 1950s car in 2023 I probably shouldn't call it a 2023 car.
Maybe but when you are buying hardware from the software manufacturer, it would stand to reason to have a reasonable lifespan.
2018-2025 is seven years of support. Apple supports iPads for like 5-9 years. I'd like for it to be longer, but it's not like Microsoft is being some kind of outlier here in the midrange tablet market.