I just read the article, it's actually pretty interesting.
The TL;DR is that there is so much observable data out there (exponentially more than expected), that Datadog, which isn't optimized to deal with that, caused their prices to need to hike.
There are two options listed as alternatives:
- Self host but it might not be cheaper
- Buy into a company that is from the ground up focusing on dealing with that massive amount of data.