I have spent 10000+ hours doing design and I've got to say that my leap into code (especially backend) has been incredibly eye-opening. I've realized how so much of design is ego-driven, how design studios design for design awards, and what a crime it is that so many technical minds are steered to work on problems more related to fashion than accessibility or productivity.

Designers should definitely code. Too much of design is siloed in fanciful thinking, and fancy people competing with fancy people over fancy things perpetuate delusion.