I think there's a number of pretty sizeable challenges any entrant into the industry would face. I agree graphics is pretty far down the list, but licenses are far from the only obstacle. I'd almost say that would be trivial, as presumably if someone wanted to chuck enough money at the problem they could probably hoover up a lot of the licenses (I have no insight into whether there's any exclusives or anything, just speaking hypothetically with it being a purely financial problem).
So say you've got the money and you've got the artists, you're still waaaaaaaay behind where you would need to be. Like you say you'd need to build the research network. Given it's all voluntary, you could maybe turn most of those volunteers over to working for your product if it's better, but that's a bit of a stretch for a completely new entrant. But say you manage to get past that too, you're still going to be way behind. I think people often underestimate just how much work needs to go in to getting the product to where it is today. It's far from perfect, absolutely (and they'll likely be the first to admit that), but the match engine in particular is the product of decades of continuous development, expertise and domain knowledge. Let's say you find someone who absolutely knows their stuff in the area but lacks the domain knowledge. You could maybe spend a few years with them locked in.a room and come up with something that comes close, but that doesn't eliminate the gap, it just eats into it, as SI have spent those years adjusting their own efforts too. Or even made greater strides.
Put it this way. EA have FIFA, which is not a great product by any means, but still sits fairly clear at the top of the pile with Konami's only response seemingly violent seppuku. Even the strung together series of janky animations they call a match engine is way ahead of where a new entrant would be, and that's in a genre that if someone could do it right, an alternative would be worth a fortune. And no-one of note has really tried. FM by comparison is a far more niche product in a far more niche genre. No-one is going to take on the considerable risk to try and become the top dog. No chance.