I'd argue that a lot of shows have fairly rough first seasons, good to excellent second and third seasons, and then start running out of ideas in the fourth season.
Four seasons is a good length for a TV show. Two is too few most of the time.
This is a very rough metric of course. Some shows peak in their first season and go downhill from there. A few manage to reinvent themselves enough each season to avoid going stale, but in general four and done is good.
I don't have any data to back this up, but I have been watching TV for many, many years. It seems to me that we have two types of television series...
1) A show that was carefully written over the course of several years and had a pretty large budget when the first season of the show was finally made. These have a good first season and maybe an okay second season but often flounder in their second season.
2) A series that maybe had a good idea and a decently written pilot but not much more on the books in terms of time investment, often having a smaller budget. These shows might have a pretty poor first season with some good episodes here and there, perhaps the cast starts to show some real chemistry as their characters begin to get fleshed out towards the end of that season. The second season only gets better as everyone has a better handle on what is working.
It could be argued in both cases that more seasons are worth the gamble. In practice, though, more shows just get worse. I can't fault Netflix for leaning towards early cancellation, that seems like the obvious safe bet.
Ya, 1 fits a lot of the big expensive dramas like The Sopranos and GoT (although waited 5 seasons to flounder), while 2 fits the comedies like The Office and Parks and Rec.
In terms of this article, I guess the important takeaway is that happened with the traditional system, before Netflix and Amazon were making their own shows. Some networks were already leaning towards cancelling early and often.
Four seasons is a good length for a TV show. Two is too few most of the time.
This is a very rough metric of course. Some shows peak in their first season and go downhill from there. A few manage to reinvent themselves enough each season to avoid going stale, but in general four and done is good.