I don't know what else to say, so I'll just give an example.
If you have a People library with entry name something like SSN or Last Name and First Name, maybe it contains a checkboxes field called Languages Spoken. A typical value might be English,French,German.
Problems with such fields include that if you then want to get a list of all folks who speak French, it isn't straightforward. Also, if you want to sort your entire list by Languages Spoken, it works a little if you make the items be in the same order that you want to sort by, but not really. Also, group and filter don't really work much at all.
I know of no solution for this. In a language like SQL or JavaScript, you can parse the values, separating out each language, and creating a result you can then sort, group, or filter by. But that's a very heavy process for something you'd rather do as quickly and easily as you could if it were a radio buttons field.
The alternative I suggested doesn't fix any of this. It's still a multivalued field, but it's an alternative. You could create a Languages library, maybe keeping other information about each language (or not).
Then, instead of a checkboxes field in People, you could use a link to entry field, and just link that entry to English, to French, and to German in Languages. Maybe it behaves a little better sometimes; maybe not.