I noticed the adblock extension on safari makes it freeze up for a second when I open a new tab. apart from that, soooooo much snappier than chrome. (desktop, not mobile ofc)
extensions in general are a huge issue for all browsers, it's easy to install a bunch of them and not notice your performances going down until a few months later, at which point you blame the browser (even for developers, evaluating the performance impact of extensions can be difficult).
That's especially true for content-alteration extensions like ad-blockers as it's very easy to implement them in ways which work well enough with few rules but degrade superlinearly at scale. That's a big part of the issues Firefox has/had (not to mention the "depth" available to XUL extensions), but it's not like other browsers are immune.
One shouldn't let an extension with access to all the pages run continuously. I wait for the day a famous extension like Awesome Screenshot will be pirated and publish everyone's bank account credentials...
Of course, between "should" and the reality, there's room for tolerance.
That's especially true for content-alteration extensions like ad-blockers as it's very easy to implement them in ways which work well enough with few rules but degrade superlinearly at scale. That's a big part of the issues Firefox has/had (not to mention the "depth" available to XUL extensions), but it's not like other browsers are immune.