I had caught all the fish and insects, I was only a month away from completing the sea creatures, I had everything paid off and enough Bells to do pretty much anything I wanted to do on a whim. After changing my island's design so many times, I've run out of ideas with what I could do with what I was presented with.
Beside playing a little daily, or just trying to find DIYs I was missing, and having to wait for random NPCs to complete things or get DIYs, I honestly just ran out of stuff to do. I ended up coming to the conclusion that a new island would probably benefit me, so I decided to restart for 2021.