Well it's tricky, since if two players are identically skilled, then they'll in theory stay completely even until something upsets the balance (e.g. a teammate or some lucky crits or whatever). Then you have two identical skill players, but one has a gold/xp advantage, so since the skills are theoretically identical, the gold/xp will give them the edge so they'll begin to snowball, and unless something else happens, it'll turn into a steamroll, despite starting from two identically skilled players.
If they're not identical skill players, then by default the more skilled one is going to begin to steamroll, so basically every option results in a steamroll of some sort. Tweaking the magnitude of the rewards can change the pace of the snowballing, but if the balance is thrown off, it's going to start snowballing.
If having a gold/xp lead doesn't result in snowballing potential, then that feels bad too, since even if you are more skilled, whatever systems are in place to prevent the snowballing and the enemy team still stands a good chance of winning (despite being less skilled).
Interestingly, if games do get to 50+ minutes or so (i.e. everyone is full build and lvl 18, removing gold/xp advantages), they often do end up being 50:50s. I feel like in a great many surrendered games, if everyone actually held out and weathered the storm without gving up or being tilted by early game, a lot more games would get to those late game stages where suddenly things feel 'fair' again. It may not be worth a players time to drag it out, but it is a way to better suss out if a player/team is winning because they happened to get an early gold/xp lead despite equal or lesser skill, or if it really was them being superior skill players.