I've used 4, sometimes 5 filters on a single SQL report. For instance: user, course, search, start and end time, on a report for course completions is a very common filter set I use. There is no problem in doing this.
However, some filters don't work well on large sites, for instance user or course filters, just because the pop up list is so long and hard to scroll through. Scrolling through 10,000 users is not practical. Even scrolling through 200 users is not really practical.
The text search filter is vey useful, but it is limited to only one instance per report. You must choose which field you want to search on. Sometimes this works great, and sometimes not. For instance, you can not search by user full name, because Moodle does not have a unified user full name field in the database, so you can only search by either first name or last name, but not both.
So, while technically, there is no issue with multiple filters, practically speaking there are real constraints to its usefulness depending on which ones you choose.