The only reason getting from 70 to 75 is a rough period is because it represents the three expansions no level increase transition from Omens of War to Prophecy of Ro, when monsters went from being barely above Planes of Power level to hitting like a truck and having three times as much health. This wouldn't be as big of a deal but for the fact that Defiant armor - the most practical option during this period - does not experience a similar increase in power, so gear progression is very limited because you will not find groups around this level and yet also cannot simply defeat the monsters you need to get upgrades by yourself, so either you buy hardcore legacy armor or you just don't upgrade. This is the only reason most people skip 70 to 75. In fact, people used to just skip all the way to 80, when House of Thule equipment becomes plentiful and powerful. These days you do have the option of doing the Broken Mirror, but you still need a box for that unless you can find people to carry you through the first missions. But you know what, this is going to happen again, in the future, when people are trying to get through the three expansions no level increase transition between CoTF and Empires of Kunark, for the exact same reasons.