Netflix series just a season?

I would like to know why there are many series at Netflix only 1 season have

I'll just assume:
They consciously only buy season after season the licenses to estimate whether it financially makes sense to put even more money in the offers to the series

If it is Netflix - independent series, then it is often the case in German-speaking Netflix that they only have one or two seasons, although they usually run longer.

I can imagine that only the permission of the producers, then the respective networks and finally the German-speaking channels must be gehohlt, until everything runs then also Netflix.

Series are produced in seasons. In most cases, one season per year is produced. The first season, the Premier Season, will be made available to the public. If the new series reaches a minimum audience or clicks in a given time (Netflix series is 1 month), another season is ordered and produced.

If a series reaches no hoped-for odds, the series will no longer be commissioned by the broadcaster or streaming service and will be put on ice until another broadcaster or streaming service / investor is interested in the format. Depending on who has the rights of a series or film series…

For the audience that is sometimes really stupid. Many times I have watched new series in which there was a season first. In retrospect, I learned then that although more seasons were planned, but no new seasons has been commissioned.

The movie industry consists of nothing but ordinary business that only produce what is most profitable and profitable for them. Unfortunately, not every series is as trendy as the trendy series.