Dimension has the same seed in every world in 1.16, how can I change this/work around it?

Version 1.16.5
In every world, the generation is the same. Now, it took me a long time to notice this so it may not be a huge problem, but, I really don't want it to ruin the experience if everyone world with this dimension, the dimension is the same. Like, they can go to a certain coord and the terrain will be the same each time. 
I have the seed set as 0 in the dimension.json file.
How can I fix this issue, is it even possible to fix it? How have mods fixed this issue? How can I work around it?