You no longer have to wonder when you can throw caution to the wind and install Android on your Switch. Homebrew developers at XDA have released the first publicly available Android firmware for Nintendo's system, a take on the Android 8.1-based LineageOS 15.1 for compatible models. It's still buggy, including issues with battery life, auto-rotation and sensitive touchscreen input, but the core functionality is there. Effectively, it's a small Android tablet with a pair of controllers attached -- you can browse the web, play 3D games and otherwise use it like you would other mobile devices.
It's even based on the Android tree associated with NVIDIA's Shield TV, so Tegra-exclusive titles like Borderlands and Half-Life 2 will run.
It'd be an understatement to say there are caveats with this firmware. Even if you can live with the bugs, you shouldn't expect support from Nintendo if things go haywire. You also need a hackable Switch in the first place, and newer revisions of the console might not support this in the first place. If you can boot into the Hekate tool, you'll know that it will work. This is the definition of risky, and you probably shouldn't try it if you want to be absolutely sure that Super Smash Bros. will still work when all is said and done.
With that said, it's a significant achievement in console modding. While you were allowed to install Linux on the PS3 at one point, this is different. You're installing an easy-to-use mobile operating system with a rich library of apps and games -- you could keep using this well after the novelty wears off.