Too Many Add-Ons Causing Jira Software To Perform Slowly

Yes, in the past.  There are three main things that happen

1.  Each add-on you have chews up a little memory permanently, even if it's disabled.  When they're active, they all cause the JVM to use more resources, as they're doing more than plain JIRA does.  The effect of that can be negligble, but in some cases when an add-on is trying to do a lot, for many usrs, that can be significant.

2.  Some add-ons can conflict with others.  It's unusual, but I have seen cases where the disabling of either A or B can massively improve performance

3.  Badly written add-ons can cause issues, especially with caching.  I could wave at some examples, but the best example I ran into was the one I wrote before I knew enough about caching and writing stuff in Java...