No, you are right. Lefties do have the advantage that side, as a leftie who plays right handed, I have the nautral advatange that side.
But at 30-30, you will need to serve at the deuce side and the advantage side so you will ultimately have to serve twice at each end. It is exactly like 4-4...
You can say the same thing about 4-4 in a penalty shootout. Effectively it is, sure. But tradition states it isn't. It makes no difference at all.
Neither did you.