I'm not entirely sure what you're requesting then. The end game monoliths start at level 58, and the lowest level I've been able to complete them without dying repeatedly is level 30 or so. The campaign skips start at level 20, and give passive and idol slots. Are you asking for the game to just start your alternates at level 60? I'm not following.
Additionally, once you unlock your mastery at the end of time, you can just go straight to the end game monoliths on a second character - there's literally nothing stopping you from doing this.
As it stands, you can skip 3/4 of the story if you use the current method. Now that you can skip dungeons and go straight to the dungeon boss, you are easily able to bypass a ton of story, and fairly quickly. I have 6 characters in this season, and i did the campaign skip on each one. You can get past the entire campaign in about 90 minutes with this method now, which doesn't seem too bad you me. You also get passive points and idol slots for completing the skips. You can actually skip almost straight from the first major part of the ruined era (level 20) all the way to the level 50 era in a matter of minutes. If you're geared up for this, go for it!
When i said i was contesting it, i was conceding to you that i somewhat agree with the skip function needing improvements. That being said, I do think as they're adding general game improvements, it is making the idea of having alternate characters much better and easier.