What is meant exactly by 'Deformable Mesh Area'? (context: Was Reading when/when not to use triangles) I have been learning basic modelling and texturing using Maya. I read many times to avoid using Tris and I can see why sometimes I get pinches or the edge flow breaks down.
But I was reading this thread: https://blenderartists.org/t/why-tris-are-bad/547399
The top answer says:

&quot;Tris have their purpose and place. Those what blindly repeat never ever use tris probably can’t even tell you why.
They don’t deform well, can cause pinching artifacts, don’t play nice with subdivision surfaces, and kill the holy edge loop.
You can use tris. Just not on deformable areas and are best avoided on large planar areas as well. They work very well tucked away behind the ears though…&quot;

It seems this guy knows what he is talking about and I understand that I should only use them in hidden areas. But what exactly does he mean by 'They don't deform well' and 'not in deformable areas'?
I googled it, it seems like any curved area is 'deformed' (https://catlikecoding.com/unity/tutorials/mesh-deformation/#:~:text=The%20mesh%20is%20deformed%20because%20a%20force%20is,entire%20object%20would%20move%20without%20changing%20its%20shape.). But is the answerer meaning deforming as in animation or live movement?
Think of an ocean surface, various sizes of waves.
where all verticles move (try it in blender with ocean modifier).
You don't get strange artifacts with simulating that with quads
Not even if you later to decide to subdivide it.
Clean topology makes life easier, but there can be exceptions to the quads rule.
In some cases a tris might bend better, depending on the shape you might need a quad to have some bending angle divinding it into 2 tris.