why are lipo's 3.7v?

[Big G]

why not make a lipo that's 1 cell and 7.4v? no need to worry about balancing it then or anything else.

Surely someone can come up with this?
Granted it couldn't be in saddles.

Just seems strange. When I left the hobby many many years ago brushless motors were only just coming out. I think novak were the only people with 1 out. When I came back in 2008 PTs, lipo, a range of brushless systems and 2.4ghz were all the norm. I would of thought a single cell lipo 7.4 would be possible?