If you follow the logic of "The power of a weapon should reflect the amount of effort it requires to obtain said weapon" and you wish to create vertical progression, you have 4 primary options:

1. Abandon the old return on investment curve, wipe the slate clean and start again (what they're attempting to do).

2. Make new weapons abide by the current return on investment curve so delve weapons require billions of plasm before they're stronger than 99 RMEs.

3. Drag RMEs along for the ride and give the RMEs an update every time the next level of gear is released.

4. Revise the old return on investment curve so 99 RMEs are significantly easier to obtain.


Option 3 seems to be what most RME holders (even the level 80 RME holders now, seemingly) are asking for. But forcing the dev team to keep this anchor tied around them will slow down all other content from being released and keep the game from changing much at all.

Now this is all assuming that we're sold on vertical progression at all, which appears to be what most people are actually taking issue with.