Should I use Migration Assistant or Start Fresh?

Use Migration Assistant, but ONLY for the user accounts.

It makes getting your mail, pictures, music, documents a nonevent.

Do NOT migrate applications, settings, or "other files", lest you bring old cruft that you may have installed years ago, and could cause trouble in a new OS. By far the most common of complaints right after a new OS are due to old extensions and daemons that cease to work or cause crashes.

If the new computer is going to be the Apple Silicon M1 Equipped Computer - would suggest Only Migrating the User Account and nothing more.

1 - Apple Silicon with either Big Sur macOS 11 or Monterey macOS 12 Only Support everything 64 bit and there is no workaround.

2 - Issues that may exist on the older computer will be migrated to the New Computer. This would badly pollute the new Original and Pristine installation of the new OS.

3 -  Applications, extensions and Software Drivers may or may not even work on the new computer.

4 - IMHO - it would be best to only install new application etc Directly from the Developer or the Apple Apps Store.

5 - Due Diligence on New Applications and make sure they are Monterey / Big Sur compatible and factor in the ARMs CPU of the Apple Silicon Computer  

I guess I would ask do you have issues on your Intel Mac? I have used migration Assistant going from my Intel Mac to my M1 Mac and no issues but I also had no issues or non working apps on my Intel. I did this process on two different Macs.

Enjoy the new machine

You are welcome and thank you too.

Do come back to the Apple Support Communities ( ASC )  in the future, if / or when additional question may arise