Calling gmail or youtube apps is already kind of a stretch. Gmail splits everything into separate web pages with the associated loading times and need to navigate back and forth. Exacerbating this is that it paginates things, which is something you only ever see in web pages. It lacks basic features you'd expect out of an application like ability to resize UI panes. Youtube has a custom, worse version of a <video> tag to prevent you from saving the videos (even CC licensed ones, which is probably a license violation), but is otherwise a bunch of minimally interactive web pages.
Maps is legitimately an interactive application, though I'd be surprised if most people don't use a dedicated app for it.
The point is you wouldn't have an "apps browser" with tabs. If something is nontrivial, launch it as an actual application, and let the browser be about browsing websites with minimal scripting like the crossword puzzle. Honestly there probably should be friction with launching apps because it's a horrible idea to randomly run code from every page you browse to, and expanding the scope of what that code is allowed to do is just piling on more bad ideas.
Maps is legitimately an interactive application, though I'd be surprised if most people don't use a dedicated app for it.
The point is you wouldn't have an "apps browser" with tabs. If something is nontrivial, launch it as an actual application, and let the browser be about browsing websites with minimal scripting like the crossword puzzle. Honestly there probably should be friction with launching apps because it's a horrible idea to randomly run code from every page you browse to, and expanding the scope of what that code is allowed to do is just piling on more bad ideas.