Fencing question - re concrete plinths

I am nearing the end of my construction journey with maybe 2 months to go and now looking at fencing
I am the 2nd house to complete on my side of the street - other house is about 3 blocks up - so have no adjoining fencing yet

have gotten 3 quotes with and without concrete plinths - have noticed some houses in my estate with and without them.
aside from keeping the bottom rail of the fence panel well clear of the ground and preventing gaps between ground and bottom of fence panel what other benefit do they serve?
being able to partially burry them i assume makes it easier to keep fenceline level on all sides

house on my garage wall boundary will be probably be 5 - 10 cms lower than me due to the way blocks were cut/leveled - based on slab heights
just trying to have as much information as possible when i start discussions with neighbors.

Do they have to be concrete ?

nope. just what was quoted to me as plinths.

I remember one way people used to make the fence higher was to have treated pine sleepers along the bottom. This also filled in the gaps.

Not sure if you could do this - ie termites etc etc.

nah not keen an anything that becomes termite food. had issues with fencing in my last place
it eventually blew down.
I will budget for the more expensive fencing option and discuss with neighbors.
1.8 or 2m height doesnt bother me that much