20+ years of experience tells me most monitoring tools aren't reasonable.
You're wrong.
As a sysadmin, I typically receive something on the order of 1,000 to 10,000 emails daily (the specifics vary by the system(s) I'm admining). Staying on top of my email stream is a significant part of my job, both in not ignoring critical messages which have been lost, misfiled, or spamfiltered, and in getting bogged down in verbose messages which convey no real information.
Alerts which tell me nothing have a negative value: they obscure real information, they don't convey useful information, and each person who comes on to the team has to learn that "oh, those emails you ignore", write rules to filter or dump them, etc.
Worse: if the alerts might contain useful information, that fact has to be teased out of them.
The problem with emails such as that is that they're logging or reporting data. They should be logged, not emailed, and with appropriate severity (info, warning, error, critical). Log analysis tools can be used to search for and report on issues from there.
As I said: in a mature environment, much of my work goes into removing alerts, alert emails, etc., which are well-intentioned but ultimately useless.
Sorry, but you're not a very good sysadmin then. You have chosen poor tools or do not understand how to distill the information. Knowing that, I can see why you think email alerts don't work. They are effectively broken FOR YOU.
It's usually not the system administrators that get to decide what the Corporate Overlords purchases or who they do business with. So I think it's pretty unfair to blame the admins for "choosing poor tools".
Once you start sending emails for things, you start sending emails for everything. It's easy to fall into the trap of not accurately categorizing what is critical (like real, real, critical, I mean it this time guys!) and what are merely statuses. So what happens is everything starts being ignored, and your systems become obscure black boxes again.