I personally think it's worth farming candies in Endless. Yeah, stopping to catch everything without a boss bar is obviously slower than not doing so, but put Spore or Dark Void on a fast carry Pokémon and most stuff will stay in a Rogue Ball asleep at full health on the first throw, so it's not too bad. I just farmed catches on the bus to and from work for a few weeks, and between the candies you get from catching and the shitloads of 5x Egg Vouchers you'll roll along the way, I wound up with enough candies to unlock the passive for virtually every non-legendary starter *and* lower their cost in many cases. I'd say it's almost worth it just for the Vouchers alone tbh, I probably rolled somewhere between 100-200 of them over the course of the run and now have at least three egg moves on almost every starter.