Finding duplicate extensions or having too many of them can actually cause issues. This includes:
- Vulnerability issues (less extensions = less security risks)
- Harder to maintain site
I want to take a closer look at the last one: "Harder to maintain site". Why is it harder to maintain a site if more extensions are installed? This often relates to updates. All extensions need to be updated - and having lots of them installed means you have to update more extensions. As you can imagine, that means more chance to break things.
What you also shouldn't do is ignore update messages. You have to realize, at some point, you're gonna have to update. Ignoring updates is a temporary solution, however it's not acceptable for in the long run.
If you're a new administrator/webmaster, here's a list of things you can go through before installing an extension. This might seem simple, but I've seen it's actually really useful!
- Do I really need this extension? Do I already have extensions installed that provide the same functionality as the one I'm about to install?
- Is this plugin still maintained? Even if an extension works on a certain Joomla! version but is not maintained anymore, use another extension - at some point you're gonna have to update your Joomla! version and the extension will break. Picking a still maintained extension in the first place is the best option.
- Is there any documentation? If there's no documentation, there's a reason to doubt if the extension is legitimate. Try to contact the author.
- Where does the extension come from? If the extension does not come from the JED, be careful!
And last but not least, don't pick the first option because it's the first option. Try to see if there are even better alternatives once you've found an extension - after all, you want the best one and not the first extension you find.
Always make sure to test bigger extensions (such as those that feature a component) on a test site - don't do that on your live site, breaking things is not wanted of course.
Best of luck and always try to get extensisons from the JED!