I use two browsers, Chrome and Safari.

Reason #1: I have an ad blocker enabled on Chrome and sometimes I copy/paste a URL that won't open with the ad blocker enabled and paste it to Safari (my secondary browser).

Reason #2: To use a site where I have two accounts e.g., personal and public/professional account on Reddit.

Reason #3 (rare use case): To occasionally get through errors e.g., a site has a bug that only shows up on Chrome. I'd try using Safari before giving up.

Yes. Firefox as primary and for general development/debugging. Safari for must-use web apps that peg the CPU on Firefox. Chrome as infrequently as possible for Postman, browser-specific debugging, and "is this only broken because the shop that developed it is a Chrome monoculture?"

At work, yes. Internet Explorer for things on the corporate intranet and SharePoint, Chrome for any other kind of web browsing.

At home, no. Safari for everything.

I use Chromium 99% of the time, and Firefox 1% of the time (only when I need to use a plugin that doesn't exist for Chromium).

I use 2 browsers. Chrome as my default and Safari as my secondary browser when requiring a secondary window

Chrome for main browsing, Firefox for testing and developing sites.

I also have Opera and IE but only use them very occasionally

Chrome - main Firefox - Security testing