You can also export the Reminders (and Calendar entries) via a Shortcut. Will export each Reminder as an ics file.
Problem is, there is no way to import an ics file, that I know of, into Reminders, be it Mac or iOS. Some third party apps might do it (for example: it appears Calendar 366 might). Google Calendar can read ics files, and then can sync over to Apple World.
ADD: Shortcut route got me thinking a bit, can also go through all the Reminders and dump an ASCII version of them. Put an odd delimiter between values, for example, FBREAK or [][][], so that can take into a text editor and convert it to a csv file which might importable someplace. Or reverse the process with a Shortcut where you can break up each line at the separator.
I whipped up a test case Shortcut to output a json/dictionary that is easily parsed in via a Shortcut and can re-create the Reminders that way. Worst case, can always run it through some *nix commands to get it into some other format that can be imported on a case-by-case basis.