The problem with Nintendo releasing a fraction of the game, and then updating it every few months means this game will severely lose it replayability sometime in the future.
In the future, when the game and its updates are no loner offered digitally, and you're left with the cartridge, unless your Switch contains the update data, you will likely be unable to obtain them any longer
With the base game, you're be missing
- Guilivarrr and pirate set
- Pascal and Mermaid set
- Diving and deep sea creatures
- Leif, Hedges, Shrubs, Pumpkins, etc.
- Every holiday event. Including Fireworks, anniversary, May Day, Nature Day... ALL events and all furniture with those
- Redd, art, museum expansion
- Expanded house storage, sitting, and other little things
- All future content (Maybe: Café, Nook's Cranny, Re-tail, QOL, etc)
Also, all bug fixes will be lost. That means glitched plots and all the other game breaking ones. The fix to special visitor for showing up at least once every 2-weeks will be lost, though not much of a problem seeing as Redd won't be a thing.
Hopefully at some point Nintendo releases an updated cartridge of the game like with Welcome Amiibo.