Under dash insulation

[Belgium R/T -68]

Have this little nice package of "original" insulation which glues under the dash on the cowl, does it do any good or could one live without it?
Don't like to glue things since I don't have the original colour and maybe sometime very far away want to go for all stock look.

Per

[Nacho-RT74]

eeeehm... keeps the heat out of the cab.

I would keep it or replace for new one, for comfortability. That stuff does not sacrifices performance but yo'll miss when is not there