I'm pretty sure you couldn't even ding 65 without XP pots when NT hit. At least, I know I did every single none raid quest in the game, both new and old, an only ended up at about a third of the way through level 64. It might have gotten better with Tyrants Forge and PTW added later on however, but on launch at least getting to 65 without some form of XP boost was a pain in the neck.
The fact that you don't need to buy the "extra flashy crap" is what makes cosmetics so appealing though. They're not directly influencing your power in game, they're not affecting other players, nor do they offer you any advantages. Unlike offering other convenience perks which can, sometimes, fall into a grey area where it's unclear if they're pay to win or not, with cosmetic items there's not even a hint of ambiguity. They're the ideal way for developers to monetise a free to play game without upsetting their players.
At the end of the day is someone else wearing a hoodie, a pink princess outfit or a bunch of cash shop items that makes them look like Ryu such a bad thing?