The most common mid-drive and the most powerful one in wide use is the Bafang BBSHD it is a nominal 1500W unit. It could probably survive 2K Watts but you would still be FAR short of an e motorcycle
I refer to people not wanting to use the pedals and only the throttle. There is an English man using a 900 dollar controller that allows him to run 3500 watts through the BBSHD. There is another Englishman that put the BBSHD on a Surly Troll for dependability in the sun ride. I believe he used a 52 volt battery and a Grin Phaserunner. with this setup and a 300 watt solar array he used around 200 watts to the motor and came in fourth place.