Rollbit NFT "worked hard" is not a good reason, the other part is. They worked very hard to provide some utility to it, it was probably decided even before they did it, what they have achieved so far is amazing and that amazingness happened via the paper part of it, the decision making process of it.
Utility and its actual acceptance from users are keys to help any product, company to succeed. Technologies are what you use to build up your products only and if your products are accepted by the people, you will get success. Else you will get failure no matter what is sort of technology you use to build your products. It is a same story for Blockchain, NFT technologies.
I mean think about it, they are just selling some images, that part is the easiest part, you find some designers and they end up drawing some stuff for you and that's it, that's like nothing at all, with just couple thousand dollars you can find people who can do it, or just your own workers could do it. But the utility idea, and connection to rollbit was the main reason for how awesome it is.
Don't limit NFT utility to gaming, art only. It can be used in many areas of society, from science (data storage, certifications for health medical records ie.) to gaming, arts, agricultural industry and so many more.
The hype on NFT since 2020 makes people confusing and misunderstood about what is real innovation from NFT technology. It is not all about Play to earn, move to earn, whatever related to money earning. It is more bigger than that.