Would you rather never build a backend again or never build a front end again?

I have no good answer to this. Both have a ton of boilerplate that gets annoying, and both have fun, exciting parts that I like to work on :)

Also, with browser APIs these days, it's pretty trivial to prototype an idea with no backend at all. Throw in localStorage or use DexieJS to wrap IndexedDB. I was able to build a video creation tool with no backend (although it only worked in Chrome, and was pretty slow :-P).