The Switch still seems fairly new despite reaching the four year mark. I didn't feel that way about other recent Nintendo systems, like Wii & 3DS at their 4 year marks (and of course the Wii U as well).
I'd probably give the Switch a 10/10 and maybe it's my favorite game system of all time. It does have my favorite 3D Mario, 3D Zelda, Smash, MK & Animal Crossing games. One big thing that kind of sucks (for me) is that I don't like the main series Pokemon games on Switch compared to prior entries. Might even skip DP remakes (ironically, Pearl was the first Pokemon game I preordered). Still though, the system seems to be doing great on almost every other front and still looks to have big games left to be released. I do also wish that their digital library of older games was better and extended past NES & SNES.