There is an opinion that the more browsers are installed on your comp the slower it works even if you don’t use them all simultaneously. This is an important issue for me that’s why I’ve launched this new topic. I would appreciate if experts answer this question.
I can’t really see how having two or more browsers on ones system - when not in use - would have any impact on overall system performance. Clearly, the more processes running, the more resource utilisation, but that’s true of any process. You say “There is an opinion…” do you have a link?
Without knowing any details or the context, I would say that it is wrong. I can’t think of anything that could cause an impact on system performance due to multiple browsers just being installed… within reasonable limits.
Technically speaking it doesn’t make sense that having multiple browser is messing with your performance. Browsers don’t have services or drivers running that would interfere even with them not running.
There could be other explanations like adding extensions to browsers over time. Funky plugins that may get installed over time. Not cleaning browser’s cache…
In general though. As a general guideline make sure to clean a browser’s cache and cookies (when cleaning from within the browser restart the browser after cleaning). Make sure to set your browser to clean cache upon exit; that helps to keep it more responsive.
When the above is not working try running the browser without extensions and disable all plugins to see if they play a role. Or try a clean install to see if a messed profile is the cause of performance issues.
In short, enough things to try first before jumping to conclusions.