Most airlines do have MAXs. Delta does not. However, they have ordered some MAXs. So they will have MAXs in the future. That will take quite some time however.

So if it's really that big of an issue for a person, then just fly Delta for the time being.

Delta doesn't have any currently, although they ordered a bunch of the MAX family that will be delivered from 2025 - 2029. It will probably be impossible to avoid them, long-term.

spirit doesn't have any of these in their fleet, but it's not the most comfortable flight