IMVHO it became a standard because of mere habit and lack of variety in keyboards space. Most "gaming keyboards" are just variant of a classic PC keyboard with aesthetic elements, "very different" keyboards, let's say a Kinesis Advantage for gaming explicitly targeting gamers essentially does not exists.
We have lost many interesting aspects of keyboards due to this lack of variety and substantial interests in design better tools, one for instance the parabolic layout meaning instead of having a flat base with various profiles in the keycaps having all keycaps of the same height but a curved profile under the switches allowing free movement of every keycaps. For some languages we have dedicated layouts generic and better, none essentially took of. We might have many functions keys, the IBM battlecruiser offer 24 functions keys since decades, but most prefer selling small keyboards at hyper big prices stating they are nicer because they are small with less keys and most people believe that's better having gazillion of layers and combinations to remember instead of moving hands a little bit and so on.
We have lost many interesting aspects of keyboards due to this lack of variety and substantial interests in design better tools, one for instance the parabolic layout meaning instead of having a flat base with various profiles in the keycaps having all keycaps of the same height but a curved profile under the switches allowing free movement of every keycaps. For some languages we have dedicated layouts generic and better, none essentially took of. We might have many functions keys, the IBM battlecruiser offer 24 functions keys since decades, but most prefer selling small keyboards at hyper big prices stating they are nicer because they are small with less keys and most people believe that's better having gazillion of layers and combinations to remember instead of moving hands a little bit and so on.
That's is, not much of a fancy story.