As somebody who has been playing consistently since hextech crafting was launched, as long as you play a wide variety of champions you own to a decent degree you'll generally end up with more chests than keys. The real limiter is owning the champions. Even if you don't perform well you can get chests by having a premade get an S- or higher. At that point having friends who play the game is the limiter.
Non-enchanter support mains are starved for honor since "Fire and forget 'you carried'" honor gets funneled onto the carry they get fed. This leaves them starved for keys. Meanwhile one-tricks and players with small champions owned pool get honors and are starved for chests.
We all have our limiters in hextech crafting. Diluting the honor capsule pool with chests would just frustrate a different part of the playerbase. The trade suggestion by another poster is a better suggestion imo. Also don't forget to spam games during events. Even without the passes you can eek out some chests with the tokens. I got a masterwork chest with my snowdown tokens and it did NOT come with a key.