P5 is Processing done entirely in JavaScript. (It’s not a Processing bytecode translation, like processing.js was/is)
This means that the code is in JS, and effectively it maps Processing so you can do it all in JS entirely.
That said, PB isn’t fully JS, but I wonder how much of P5 can be implemented into PB (and vice versa what can’t), with an eye toward future code suggested “development” areas for PB