If the WoL wasn't around most events would have played out very differently. The acians wouldn't need to keep (indirectly) summoning more and more primals because the first few would have gotten the job done. The Flames/Maelstrom/Adders probably would have killed Ifrit/Titan/Garuda, but not without huge losses, and no one would have been able to stop Ultima (the blessing of light is literally the only reason we didn't get 1-shot by ultima.)