I'm being a bit provocative here. But, in my Drupal days this question came up from time to time. I've build some sites that use a LOT of contributed modules (70+ maybe more). I once asked a more experienced friend if I had to many modules installed. He looked at my site and said I was probably fine, but one more module might be too many. ;-)
I know that experienced coders with the ability to write custom code are sometimes critical of sites with lots of modules. I'm wondering how folks feel in the Backdrop space. Do you have any sites with too many modules? If so, what is the magic number?
NOTE: I'm reasonably sure that no one is going to provide an actual number, because there are lots of factors and different modules have a different impact on the site performance. So, I suppose the real questions are:
1) Is this something that even concerns you?
2) What factors/criteria would make you think that a site might have too many modules?
Comments
There is no such thing as 'too many modules', provided they are all in-use and have a purpose.
What is a problem is when a site is old, has had modules installed then disabled (or even left enabled) but not uninstalled, is upgraded between different major versions, etc. Then there are modules that are unused and causing bloat and possible security issues. That's when there are too many modules.
So it all has to do with how well a site has been designed and how well it's maintained, I think.
The amount of modules you can safely use also might depend on the quality of your hosting. The more modules you need, the better the hosting should be (memory, cpu, disk latency...).
I don't think that there's a "magic number" - it really depends on the purpose of your web project.
Another thing BWPanda already mentioned: the number of modules has influence on maintainability. Bloated web projects are much harder to maintain than slim ones.
That's why I always avoided Drupal distributions. The rare cases I had to deal with them is when I took over stalled/broken projects to get them up and running again. ... Which makes clear that I'm one of those who try to keep it simple and only install the modules I need. ;-)
The size of modules and what they affect on the site varies quite a lot. I'm in the habit of making tiny modules that only tweak one part of a site. Might involve a hook or two. Compare that to huge modules and it becomes trying to compare apples to oranges.
The amount of code does affect speed but PHP can cache that. Even more importantly are inefficient modules that bog down the database.