Recently I have dealt with several WordPress websites that have fifty or more plugins installed.
Unfortunately having that many plugins makes it very difficult to isolate issues. As plugins can conflict with each other, there are at least thousands of possible combinations of conflicts with fifty plugins.
More plugins also makes updates more difficult, as there are more to keep up-to-date, and brings with it a higher risk of security issues as there are simply more plugins that could be vulnerable.
Before you install a plugin think, “Do I really need this?”. Should you do decide that you need the plugin, document what the plugin is for, as it is easy to forget over time, especially if you have more than a few plugins. If you no longer need a plugin, deactivate it and uninstall it.
Should you get to the point where you have more than about 10 or 15 plugins consider hiring a professional WordPress developer. He or she may be able to find a better solution.