D&D 5E - Magic Items to boost spell attacks

I am not saying every warlock is going to get all three of those items at their highest rarity and use all three of their attunement slots on them, but it is pretty freaking silly that it would all work together if they did.

I think it is reasonable to assume very powerful wizards might eventually get both a Robe of Archmagi and one of the other items like a staff or wand in the same campaign and want to use both, for a combination of +5 and that is pretty broken.