The "best" does not exist in a vacuum. The "best" gear is useable in content other than the "most difficult".
I know its a hard concept to accept after years of having it be a certain way in other games, but the "best" gear does not have to come from the "most difficult" content. There can be other rewards for doing the "most difficult" content. SE has chosen to keep the level of player power achievable fairly level for everyone regardless of the content they engage in which is a GOOD thing in my opinion. It keeps the gap in player power relatively small regardless of the content engaged in which has benefits. Players who do non-raid content exclusively but then decide to dip their toe into the raiding waters aren't so laughably undergeared that no one would have them. It also benefits raiders by not having gear as an obstacle to recruitment when members of their static invariably suffer burn out or have to stop raiding due to RL reasons.
What you "need" as far as content goes isn't relevant. I keep saying that but I don't think you or many other people get it. It doesn't matter what you "need". Player power is one of the primary motivators to play the game. SE has a vested interest in people playing the game. There is nothing gained by keeping the heights of player power exclusive to players who engage in in only one certain type of content, and there are definitive benefits to doing the opposite and allowing players a variety of ways to earn similar gear and advance their characters REGARDLESS of what content they engage in.
The reward for raiding in FFXIV is not "the best gear". Many people struggle with that concept, I know. But rather the reward for raiding in FFXIV are exclusive appearances from raid gear, getting "the best gear" much faster than those who don't raid, unique mounts, titles, and the satisfaction of completing that content. Why does raiding have to reward more than that? I have yet to see anyone answer this question.