I rarely, if ever, walk or run toe-heel.
Tippy-toes, sure. To be very, very, quiet.
If the surface is very rocky I might go flat-footed
to increase the area which makes contact
and enable better balance, etc.
To not bruise or puncture.
Going slow can be good.
I've read about toe-strike running.
It makes mostly no sense to me.
Maybe on grass. Even then,
I don't normally run that way.