Here's an article about it: https://netflixlife.com/2020/09/28/why-did-the-good-place-en.... I know some other sites report that it was cancelled, but even on the The Good Place Podcast, no one really talked like it was being cancelled versus reaching the end of the story (and not jumping the shark).
Yes, it was.
> but it wasn't a Netflix produced show anyway
Which is orthogonal to the point of raising it as an example of how a cancelled show can end in a satisfying way.
Many broadcast shows that are constantly on the bubble write their season finales to double as series finales in case they don't get renewed, see for example within just the past 2 seasons: Brooklyn 99 (cancelled but renewed by different network), Fresh off the Boat, Lucifer, Single Parents, Crazy Ex-Girlfriend, Lethal Weapon, Star, The Orville (cancelled by Fox, picked up by Hulu, cancelled by Hulu but given final season pickup).
It's not an incomplete show like, the Santa Clarita Diet, for example (which I'm still mad at Netflix for cancelling, it was just getting really good and ended on a cliffhanger).
If The Good Place was 'cancelled' (which I'm pretty sure it wasn't), they were at least told in advance of the 4th season and were given the full season to finish its story.