I think this has been pretty covered but Ill add my two cents.
Of course you dont "need" a high end fly rod. We dont really "need" much in our day to day lives. So the question is "want" and what is the benefit?
I own three premium rods and I have some serious dough wrapped up in them. Two Orvis Helios and one Hardy Zenith. I feel like it is money well spent and I wont buy another rod for probably 15-20 years.
Do I perceive a marked performance increase over my prior mid tier or low end rods? Absolutely...better rods, better reels, lighter, faster, distance, accuracy, you name it...all better. Does it help me catch more fish or trophy fish. Probably, but only marginally.
You could use a stick and a leader and if you present the right fly with the right drift you'll have a fish on. Your skills and fly selection will always trump rod performance. But I think its like driving a luxury automoble versus an every day car. Same functionality, but you sure as hell appreciate of the "premium" you paid for the luxury car. They are just better.
That being said because its a "want" only you can determine if its money well spent. Me? I would say yes....