Let me give you the usual scenario:
Map: Fairground
Your team: Green
Their team: Orange
Orange rushed mid pretty much as soon as they had access to blocks, and a minute or so later the 2 others came with decent gear to control mid. The naked one, got enough for a bow and a dozen arrows. He can basically prevent anyone from continuing the bridge.
BEFORE mr. naked got a bow, the others had to deal with you guys ALSO coming to mid. They managed to kill you off, and they decided to run over your bridge as far as they could before you could punch them off. When they reached their destination, they decided to break all of the bridge, and by the time they already finished, mr. not-so-naked-anymore got a bow. Now what do you do? You had a shot, but you couldn't make it back with diamonds. The other teams tried rushing each other AND orange, but failed due to the bow & good defence. Orange lost their egg in an attempted rush, but that doesn't stop them from mid camping. Nobody but them have bows, nobody but them have diamonds. Tell me: What can you?
Levitation potions could work, as long as a single potion is worth more than a layer of obsidian. Else players would just use this to rush nearly naked & pop other eggs with no effort.
Test what out exactly? 'Cause mid camping has been proven not to be too hard to do.
I do have one more question for the levitation potion, though. What do you do about the received fall damage after landing on mid? You're there, little health, they're hitting you while you're trying to regenerate. What do you do? Add a feather falling enchantment somehow? Actually, that might be a neat suggestion I could do...
I don't really feel like picking a specific kit to benefit in a somewhat rare scenario, so what can we do?