I play both to various degrees of incompetence.

I started with the piano and got a guitar at some point after. Neither one is actually "easy".
The piano is good for visualizing music theory. Learn a few simple chords on the guitar and you can start playing songs quickly but the same thing is possible on the piano.

Mastering either instrument takes years of dedicated, concentration and practice. The more you learn, the more you realize there is to learn.

The piano is simply 88 keys. The guitar is 6 strings and a multitude of different tunings of those strings.

It's not easy to pick one to say which one is harder. Neither one is easy to get proficiency on without a lot of time spent on the instrument.

You can find my music at:
www.herbhartley.com
Add nothing that adds nothing to the music.
You can make excuses or you can make progress but not both.

The magic you are looking for is in the work you are avoiding.