Runes are the only real custom touch to be added in the game. Without them it is just the same heroes against the same heroes, along with other benefits like being able to complete higher temples, currently temples dont really go more than 70 levels above max team level. Which is only 4 temples after reaching the 10 scrap reward max. S5 alone has completed temples up to 575 levels above max team level and counting. You only start running into instant white skills and hectic battles around o7 or o8, and they have and will add new heroes and new legendary skills to combat the issues. Without runes it is false advertisement because they have said and promised we will get runes in the future, and many only play and spend large amounts of money with the expectations to at some point have runes.