WordPress plugins are simply add-on functionality you can add to your website.
There is no right number as to how many plugins one should use, but if you start to use too many, you may find your website getting slow over time.
In general, the golden rule is to keep plugins down to a minimum as you may get plugin bloat, database bloat and a website that is slow over time - not fun to work with and not fun for your users.
Here are a few interesting plugins we have come upon with keeping your database lean and your website clean.
If you are using page builders such as Divi or Elementor or the others out there, revisions tend to get big and bloat over time.
As an example, on one Divi-based website, revisions were over 100. Why keep that many revisions in your database?
Here is a plugin that should help