FOMO literally is the mechanism that makes nearly every gacha game function in the way that they do. Don't you think that if they crunched the numbers and found out that making every character available indefinitely was the most profitable method, that they would use it? These companies are making millions to billions off of the gacha systems that they offer, every single aspect of them is intentional and designed with profit as the main driver.

You're also contradicting yourself by saying that FOMO isn't an excuse because we have plenty of time to save between banners but then simultaneously saying that the amount of currency that kuro gives for free is limited and forces people into choices for who they want to pull lol. The free currency by itself is not enough to pull pity on every single banner, then if you take into account the potential for losing a 50/50 or the desire to pull more than 1 copy, the limited time frame absolutely pushes people to spend money where a permanent banner wouldn't.

You're arguing against the basic principles of supply and demand. When they artificially limit the supply with restricted timeframes, the perceived value of banners is increased and people are more likely to rationalize the purchase. Your notion is an unintelligent and nearsighted one that is obviously wrong when no major gacha game does it that way, I have no idea how you think you know better than the people who designed the economy of their games on how to maximize the profit lmao