How is it that ETFs/ETPs/ETNs don't have a ticker paradigm?

-One for ETNs/ETPs like, say, ~USO
-One for ETFs, maybe *QQQ *300QQQ instead of TQQQ.
-Mutual Funds, like "MF" prefixes

The numerics denote the leverage (*-300QQQ)

Leave the alphabet for pure, 100% Companies.

$SPX