Just because a few bosses require plat items to be taken down doesn't make the entire game a pay to win, that's simply just being overly dramatic. Even though plat items are necessary to take down those bosses you still don't see every single person taking out there wallets just for one boss because why pay when you can buy off of other players. And since everyone has Lixs at endgame (or should) no one has an advantage over anyone.Like I said gb15, when a clan manages to kill gele unlixed, no restos used, and no idols used then I'll believe the game is not p2w.
When you say a game is a "pay to win" then that means that plat buyers will always have an advantage over none plat buyers in all Aspects of this game. Leveling, gear, bosses, PvP, fishing, etc... And otm has done a very good job at keeping this game balanced between non plat buyers and plat buyers. It use to be way worse back in the day but otm has been doing nothing but making things easier for non plat buyers such as reducing low level lux prices, bounties, bounty shop, fishing, and even raid bosses because raid gear can be just as good as lux items. Oh, and you can't forget about the newest feature, the XP curve
You could argue that pets and battle mounts give an unfair advantage at boss battles in which they do in a way but that's one single aspect of the game and even then the gap between plat buyers and non plat buyers is minimal.