More capable mechanical focal plane shutters with a flash sync speed of 1/200s or faster do not show objectionable rolling shutter effects for most practical stills photography, including wildlife and most sports. Better mirrorless cameras use the same types of shutters.
Older film cameras may have had flash sync speeds of 1/60s, and rolling shutter was sometimes a problem with them.
Mirrorless cameras also have a fully electronic shutter, for silent shooting and shooting video. (Some DSLRs could also shoot video this way.) In all but a handful of very expensive cameras, it takes a long time to scan the sensor and rolling shutter is obtrusive – in many cameras it is as slow as 1/15s. In that handful of expensive cameras it is around 1/200s, like a fast mechanical shutter. Nikon’s expensive cameras don’t even have a mechanical shutter any more.
That last bit of speed, from 1/200s to the 0s of a global shutter, is detectable in certain examples Sony showed off in their presentation. Most of these examples relate to high-end sports photography.
Flash sync at any speed means flashes can be built more cheaply and cycle faster. Currently, to shoot faster than the flash sync speed the flash must emit a long burst instead of a single pulse. For this reason, some cameras used a leaf shutter, which can sync at any speed, but they were typically expensive to make and sometimes less reliable.
There are related problems to do with the refresh rate of LEDs in the field of view, which are solved by the global shutter and somewhat clumsily worked around in cameras without one by trying to sync the shutter with the refresh rate. Again, high-end sports photographers are the ones who usually encounter this problem.
So the global shutter will have no benefit today for most users.
In the future though it means we can do away with the mechanical shutter which in theory means smaller, cheaper, more reliable cameras.
However the capturing photos when you hold the focus button down feature will I think be genuinely useful for pretty much everyone. Especially in family situations with kids, pets etc.
> So the global shutter will have no benefit today for most users.
It will have a benefit for anyone who is also recording video using their DSLR, likely the majority of users. It completely eliminates rolling shutter. Now, is it a benefit that is worth paying $6,000 for? That is a good question! For most users, probably not.
> Now, is it a benefit that is worth paying $6,000 for?
This tech will certainly reach all levels of the consumer market. Plus being able to shoot with flash at any speed will indeed benefit tons of amateurs who will be able to do away with the stupid artificial limitations present for the last 150 years
> In the future though it means we can do away with the mechanical shutter
The future is a year ago: The Nikon Z9 and Z8 cameras have no mechanical shutter, and their electronic shutter speed is so fast that there is no practical issues capturing even fast motion.