Is it popular for PC Chassis with big fan like 25cm ?

It’s uncommon to find cases with fans this large. 12cm is a common large standard, but I have seen a few cases equipped with 14cm fans.

Larger fans can move the same amount of air than smaller fans, at a slower rotational speed (quieter), or move more air at the same rotational speed (louder). A very large fan would be a good idea, if you could get away with running it at less than say, 800rpm. If the fan will be running at >3000rpm, then really, it’s utterly pointless.

Basically the question is whether this a gimmick, or good design.