Font size is capped at 1000 pt. To make text larger, outline it so it becomes a shape, then scale the shape.
Scale text beyond the size cap
Duplicate the text object so you keep an editable copy. Hide the copy or move it off the artboard.
Select the text you want to enlarge.
Open the Text menu and choose the outline option. The text becomes a vector shape.
Scale the outlined shape to the size you need.
Outlined text is no longer text. You cannot edit the wording or change the font afterwards, so keep the editable copy from step 1.
When you need to change the wording
Edit the text in your editable copy, then outline and scale it again.