It doesn't actually work that way in reality. If it did, there would already be another massive Uber undercutting Uber in eg the US market and raising $10+ billion in VC money to do it. Because hey, a $75 billion valuation is sitting right there, so it's really easy: just put $10 or $20 billion into the company, undercut Uber, IPO, easy return. Everbody can do it, just add $20 billion.

What's actually the case, is the next clone will need $20 or $30 billion to fight and undercut Uber's entrenched brand, functioning system and scaled up position. And even in that case, the odds of winning against the large incumbents is low. It will cost even more to beat Uber via the undercut game than what Uber has already spent, because you have to take the market away from them - always a dramatically more expensive and difficult proposition.

VCs are not going to continue to burn massive amounts of capital trying to fund the next loss-making ride hailing company. The next $10 or $20 billion to put into an Uber clone in its major markets, does not exist and it will never exist.

Few things would scare a VC more than having the pitch that your plan is to destroy twice as much capital as what Uber did, to unseat Uber's entreched position, with nothing to differentiate you other than the speed at which you destroy capital.

That's why nobody is doing it right now. There isn't another Lyft, much less another Uber. Softbank isn't looking to drop $20 billion to fund the next Uber, to fight with Uber, in the US and similar markets that Uber dominates now.