With raids now being a part of the game walking 5km to get one candy over and over again for most top tier pokemon is just inefficient. Maybe make it so the more you walk a single pokemon consistently the more candies they earn for the walk (eventually getting 2 or 3 per cycle instead of just one maybe). The system feels heavily unrewarding now and the last time i felt like the buddy system made a difference was during the event where buddy distance was shortened as i actually was earning candies with it at a decent rate instead of walking 460 km or more to get a dragonair to a dragonite. Sure you could argue hatch more of them or catch them but when you live in an area where Ive seen a grand total of three vulpixs spawn ever (two of which were during the solstice event) whilst playing daily then it gets extremely discouraging to continue trying to catch them and you end up walking with them instead to evolve.
JimCarry349 about Pokémon GO, v1.37.2