This I think is obviously personal preference, but to me nested ternarys are pretty readable as long as they're wrapped and indented.

When they are, you basically get something that looks visually like a decision tree. This can read really nicely in situations where declarative style code fits better - for example embedding nested ternarys in JSX is quite a popular pattern for this reason.

The caveat is, you have to be 'used to' reading the ? and : symbols and instantly mapping them to if/else, but I certainly don't think getting used to this in a short time frame is beyond expectation for someone who's not already, i.e. new team members etc.