This is a problem that is so incredibly solved it has spawned a giant industry of SaaS providers preying on the fact that a lot of engineering managers don't really understand simplicity. Raking in the cash without doing much of anything.
Out of interest, what makes you think there's still money left on the table in this domain, given all the existing products? Or rather, what do you feel all the existing products lack?
This is one of those examples that I liken to the dry cleaning business.
In any given city there may be lots of dry cleaners available. Some will be much better than others (service, performance, etc.). Some will be much cheaper than others. Some may be the perfect combination of all these things.
Unfortunately, we often don't know where the best one is. And perhaps because of another person's suggestion "affiliate marketing", it is now virtually impossible to search online to get actual reviews of things (as there are now more SEO-d review sites which are just thinly veiled affiliate marketing sites).
So we use the service we see nearby or stumble upon. It may not be the best, but we don't really know better.
The same applies to so many things in life, business or otherwise (people, friends, relationships). Thus, yet-another-monitoring-service can succeed if it gets enough customers, even if there are much better services out there.