In the beginning there were only ante's, and that was fine, except they were a pain in the ass to keep track of, so some smart fellow invented the blind and at first there was only a single blind, and that was Ok too, but the pots were small, and there was no great reason to gamble, and everyone wanted a little more, so a 2nd, and bigger blind was invented, and it was better! More of a gamble, more "ACTION".
So the straddle is a stretch of the concept that the more the pot is, the more it is worth getting involved in trying to collect the pot. And the more reason to gamble.
The game will play differently with a bigger dead money pot. Different odds
would be applicable if you play a standard game, and have figured the odds for that standard game.
Under normal circumstance all at the table would be straddling, or none would.