There’s always emulation, and that you can easily do on the go. So if you have a commute or other extended downtime away from your TV, that may be an option.
It all depends on what you play. You’re definitely in dangerous territory with anything from the PS1/N64 generation, those early 3D games are often quite janky and ugly as sin. But if you go with 16-bit and 32-bit systems like SNES, Mega Drive/Genesis, and Game Boy Advance, there’s plenty of games that hold up really well.
I absolutely loved my recent playthrough of Metroid: Zero Mission, a GBA game that most certainly holds up and that I wouldn’t hesitate to recommend to any fan of the Metroidvania genre.
As to the question of the thread: No. I have very little interest in light gun gaming. It can be fun in an arcade setting with a friend once in a while, but not fun enough for me to spend money on an accessory like that.