The argument can be made that non-parents shouldn’t use the 529’s for the “future” student. They’re better off paying the tuition directly which doesn’t count as a gift to the IRS.
As for a 529 owned by the parent or student, you could invest in 401k/IRA instead, but there of course are limitations associated with those vehicles vs 529. https://www.cappex.com/articles/money/how-to-shelter-assets-on-the-fafsa
