In my app I collect names in separate fields. It forces the user to insert names properly instead of mixing ‘First Last’, or ‘Last, First’, etc. I have a template column that joins it into ‘Last, First’, so it’s always sorted by last name first. It’s all your preference, but that’s what I do.
If you wanted to collect it in a single field, then I think you would still have to split them in a google sheet to get separate columns to sort by. You can split in glide, but you can’t work with each split value individually.