I'd say that the main challenge for vibe-cloning big and known programs comes down to cost. Plenty of extremely competent devs and companies out there are porti

I'd say that the main challenge for vibe-cloning big and known programs comes down to cost. Plenty of extremely competent devs and companies out there are porting FOSS programs from one language to another, while offloading all the heavy lifting to the AI models - but even then, it can cost a non-trivial amount of money, and we're still talking about programs which are 1/10th in size of the ones you've mentioned. I'm not sure exactly how many lines of code say Excel is, but if we estimate 10 MLOC of closed-source, then it would take a serious pile of cash for some SOTA LLM to reverse-engineer it. Especially given the fact that we don't have the code at hand to port. Of course, we could use some open version of it, as best approximation, but there's still a ton of reverse engineering involved, which will burn tokens like crazy. So the question becomes: What incentives are there for lone devs, or smaller teams, to vibe-clone some of the products, if it is going to cost them a fortune to do so? These things need funding.