Tested Version: 21w13a
This is simply a custom world setting that I created on this website here. It's an experimentation I did where I basically raised the size of the biomes so large that they basically are the size of continents with realistic ocean sizes too. As of right now there are only 2 biomes, Ocean and Plains.
When you load it you most likely will spawn on an island, basically stranded in the ocean. For those who want to find the coast of a continent, follow these steps:
1. /locate village
2. Teleport to said village
3. /locatebiome ocean
4. Teleport to said ocean

I wasn't sure what to list this as, but if anyone has a better category for it please comment it below.

While I did use a website to generate the file itself, I did edit the parameters to make it specific to my liking.

How to use:
Step 1: Extract the Zip File.
Step 2: Open Minecraft and Navigate to "Create New World".
Step 3: Go to "More World Options" and Select "Import Settings" and then Navigate to the Extracted File.
Step 4: Select "Realism.json" and click "Open".
Step 5: Load the world!