Interestingly enough, Spells like "Globe of Invulnerability" have a material component that is consumed (glass bead). If you use your Arcane Focus, I suppose that would be consumed as well - bye bye focus. Note, this is not like Raise Dead that uses a 500gp diamond (ie you MUST have a 500gp diamond).
Of course, I think the intent is: Use whatever floats your boat. (levitate, nyuk nyuk)
A strict reading would destroy the pouch or focus when a spell consumes its material components though I suspect strongly that wasn't the intent.
Basic Rules pg 79 said:Material (M)
Casting some spells requires particular objects, specified in parentheses in the component entry.
A character can use a component pouch or a spellcasting focus (found in chapter 5) in place of the components specified for a spell. But if a cost is indicated for a component, a character must have that specific component before he or she can cast the spell.
If a spell states that a material component is consumed by the spell, the caster must provide this component for each casting of the spell.
A spellcaster must have a hand free to access these components, but it can be the same hand that he or she uses to perform somatic components.
(emphasis and whitespacing added by me)