I think sometimes on forums and YouRube comments sections, too many get jumped on for wanting fast lenses with the often false assumption it’s all about getting the most shallow DOF possible, but for many of us, that is not the primary driver which is low light capability, ie, without the picture turning into a muddy mushy mess.
Personally, I do like a shallow(er) DOF, but then for me it’s not a fad but something I have preferred for 25+ pro years.
But not the razor shallow f1.0 in bright sunlight shallowness that causes all kinds of issues, more some clear separation and modest background blur rather than obliterated any and all context.
Focal length can also of course remove said context so it’s all about balance and intent.
In good light, outdoors, nothing much in it really but it’s definitely easier/more options with full-frame for low light.
I don’t have anything faster than f1.8 for primes and no issues with low light.