&gt; <i>The renderer is not some minor detail like how tcp connections are made, it&#x27;s practically the whole thing!</i><p>It&#x27;s totally not.<p>All the things you list are just components of &quot;showing a web page in this rectangle&quot;. That is akin to &quot;how tcp conections are made&quot;. The renderer used to be <i>hugely</i> important because many renderers didn&#x27;t work at all for some sites and features, or were massively slow. That&#x27;s still true to an extent and why the renderer is still an important point.<p>But the <i>browser</i> itself is more about application features (and maybe cloud features).<p>How do you manage windows? How do you manage 10 tabs, or 250 tabs? How does it store your passwords and how do they sync across devices? Can you pull out your phone and easily jump to a web page open on your desktop back at the office? Does the browser crash a lot? Can the browser remember your font zoom settings for each site you visit? Can you override preferences for certain websites conveniently? How can you visualize the current set of websites you are on, or this history of sites you have visited. Can you easily restore a bookmark set of twenty websites? If so, does it restore your window sizes, positions, and tab order? Can you easily identify which window&#x2F;tab is making annoying sounds? Does it have a 1Password extension? Does it override standard OS features like Print (to PDF) with its own lame-ass UI for the same thing (lookin&#x27; at you Chrome)?  When you copy text, is it smart about putting the different representations of the copied data on the clipboard so it works optimally whatever app you are then paste into? Does it let you have different profiles to keep e.g. your work cookies separate from your pr0n cookies? Speaking of cookies, how easy is it to inspect and deal with them? How does its extension mechansim work, and what is its defense story against the installer-malware that comes with e.g. Java? Is it fast to launch? Can you easily re-open closed tabs and windows? If so, do they retain their state and Back&#x2F;Forward history? Can you easily customize things like font and zoom and override bogus sites? Does it have an ad-stripping &quot;reading&quot; mode or does it need an extension? Etc.<p>In modern times, those things are a lot more important to me than the renderer (unless the renderer is broken).