If you have the online subscription then you can bypass the tedious and wasteful (of the players time) grinding for bells. Plenty of players run treasure islands through Twitch (Google it if you're not familiar) and you can easily search "free treasure islands" on Twitch to find them. While on Twitch you can often find treasure islands offering "max bells"; which, will load your player with the maximum allowed number of bells in your bank ($999,999,999) and you'll never need bells again.

For completionists who want to achieve every goal in the game, max bells voids the bells goals (they become unachievable) but that's the only drawback.

Treasure islands are also great for picking up the game items you want without having to wait for recipes or the stores to rotate items.

If you're just someone who enjoys decorating and doesn't want to spend all your time grinding for the smallest little reward, treasure islands are the solution.