#1 To justify the Wild Card rule
One of the things that Mick Foley mentioned is that the title will not just be confined to RAW, but also to SmackDown Live, NXT, 205 Live, and NXT UK. What this basically means is that anyone could show up on RAW as a part of the Wild Card rule and take the title to their respective brand.
I suppose this is the best use of the Wild Card Rule since its inception. Now, there are 4 Superstars that could potentially show up on any brand from another brand and take on whoever the reigning Champion is at that point.
The Wild Card Rule is basically just a ploy to get big stars like Roman Reigns and Kofi Kingston on both brands. But now, there is a greater sense of purpose to the rule because of the 24/7 Title.
Maybe it'll also get more eyeballs on brands like 205 Live.