Stamina in games is not a good mechanic
I have heard a few reasons as to why Stamina is a main feature in most Gacha games. To slow down progression and make people log back in a few times a day, prevent addiction in people who may spend 16 hours a day on the game, and prevent people from finishing the game in like 1 day.
I think those first two excuses are just BS and the last excuse is completely irrelevant. The Energy/Stamina mechanic is just a way for games to limit how bad their game is by limiting how much you see in a day. Because if you had access to the entire game all at once, you would realize halfway through that most of these gacha games stories are so similar that you could give a description of one game and people would confuse it for another.
Gacha games are inherently addicting, thats the entire business practice of using Gacha in the first place, to make people want to gamble and spin the wheel until they hit gold.
90% of gacha game players don't actually listen or care about the story, and the game creators know that, which is why the story is usually bad to begin with. Slowing down progression almost never works. Big spenders are going to get the energy back, and even small spenders will have the magical Battle Pass-esque shop item that gives an extra % of energy every day.
Energy systems are just a way for the games to milk money from people. Lets honestly call Gacha games what they really are, Subscription based games.