Of course it's not necessary There will always be ways to get 'good enough' weapons in the game, depending on what content you do. But you don't really have to invest a whole lot of time into it, I dont get the people who spent weeks just grinding out fates and the others who complain about low drop rate, the whole point of the system was to take a while since people complained there wasnt enough to do in previous patches. You can just go do some fates occasionally when you have nothing else to do/waiting on queues, buy books when you have the myth to spare.