Is mining a 1x2 hallway too slow? Do you not enjoy watching your life slip beneath your fingers just to acquire in-game resources? Then the haste potion is for you! Definitely not an original idea, I just couldn't find any for 1.16 and wanted to try to program something (pro tip, don't try to program things if you're stupid like me). Simply combine awkward potions and honey in a brewing stand to create one, and you can do all the vanilla potion things too to enhance/lengthen the effect, or turn it into a splash/arrow/lingering potion (but why tho). Additionally, if you're lazy you can get an extended and enhanced effect by brewing in a golden pickaxe. One more thing, technically you could also use this combat since it increases you're swing speed I think.
Big thanks to youtubers Mr. Pineapple and Optimistic Nanobot on youtube for tutorials on how to do this stuff, as well as a guy on the forge forums.