It’s less that they’re easy to get without buying them with real money and more that they’re supposed to be acquired slowly and, when relevant, used sparingly.
My frustration with the discourse is that so many who see the game’s general lack of convenience see that through the filter of these microtransactions and assume ill intent on part of the actual game design when really it’s just genuinely idiosyncratic like the original was.
The truth is, if you’re the sort to be tempted by these purchases in the first place then you’re not the sort of person who would enjoy the game even if you do buy them. I don’t know whether that makes them better or worse, honestly, but if you buy the game it at least doesn’t rub your nose in them like Assassin’s Creed.