The 3DS could not with all games, but yes most games. The 3DS wasn't competing with any other consoles and didn't struggle to run its games, which is why they were able to keep a section of memory/power for the browser and other mini apps. The Switch is directly competing with Xbox One and PS4, and its power is just enough to run its games, which means that they can't set aside a sufficient amount of memory to run an internet browser that well. And in that sense, why include one at all.