The value of Nintendo Switch Online comes down to how you choose to utilize it. For games like Super Smash Bros. Ultimate, it feels like a waste, because they’re so behind on server maintenance that the lag and communication errors are inexcusable at this point. On the other hand, games like Mario Kart 8 Deluxe and Pokemon Sword/Shield are typically fine as far as stability goes.
I personally love the free access to so many retro NES and SNES titles, and $20/yr is worth it for that alone for me.
I put it on a shared account, and Online puts a smile on my oldest nephew’s face. In many ways, that’s enough for me.
I’ll add that, barring Mario Kart, I’m really not one for online multiplayer. Though recent nostalgia overloads with Donkey Kong Country and Donkey Kong Country 2 on the SNES Online aren’t anything for me to complain about either. They’ve certainly gotten a lot better in choosing games for the NES and SNES Online games, imo. (For a while there, their choices of games to add were massive WTFs.) Though it’s still no true replacement for Virtual Console.
My wife just bought the family plan for $35 at Target. Personally, I like the SNES and NES games on Online (my hope is that they add old Gameboy, N64 and GC games to it). We mainly use it for Animal Crossing and Pokemon Sword/Shield.
I have a friend that has me on their family plan. Were I by myself, I wouldn’t pay for it. Aside from the occasional Nes or Snes game(Which I own most of physically), it just hasn’t been worth it to me. That’s not to say it won’t improve, but I just don’t think it’s where it should be three years in.