neobolts
Explorer
Part of the problem for me with arbitrary leveling and story awards is that those things presuppose a story or plot in the game, when it is my contention that story is what emerges from play, not what drives it. That's not to say you can only give XP for for killing things and taking their stuff. The things you reward XP for are, IMO, the things you are asking your players to engage in.
Yeah, the XP awards in Numenera felt pretty arbitrary at times. For the 5e game I'm hoping to cut down on that. When the players decide to take on something, they are getting clear objectives with assigned XP values, essentially a quest log. This campaign has a lot of lore and political intrigue from the outset, so the players are expecting a story to be in place for them to dive into. That said, the game will still progress organically. When they surprise me by deciding to take on some task unexpectedly, it will get added to the quest log as well.