If you have ever used a ratchet wrench for nuts or bolts vs. an open-end or box wrench, the difference between the ratchet screwdriver and a regular one is much the same as the difference between using a ratchet wrench vs. an open-end/box wrench to tighten/loosen a nut or bolt.
The ratchet in their screwdriver, from the video, has a ratchet sound very similar to the Snap-On model I have.
[1] Current version: https://shop.snapon.com/product/Standard-Handle/8-3-4%22-Rat...
It seems similar to the "why do precision screwdrivers have that spinny part on the back?"
This allows me to keep a good grip and the pressure on the screw all the time, ensuring the screwdriver head doesn't slip out of position.
I also find it faster to just twist the shaft of the screwdriver once the screw is loose, something which I find easier with a ratcheting screwdriver (many have a knurled section on the shaft for this).
And a good ratcheting screwdriver allows you to lock the mechanism, so you have the best of both worlds.
I never really liked ratcheting drivers but I might make an exception for the PB Swiss (jury's out on the LTT driver). It feels like a real screwdriver when you lock the ratchet.
It is hard to trust a “brand” any more. From 2017 there is a great summary of brand ownership here: https://www.popularmechanics.com/technology/gear/a28359/mega...
The consolation of design and manufacturing has lead to some quality problems for existing hand and power tool brands.
I guess it's just a personal preference thing rather than a real need of some sort, which IMO is fair enough
This can be annoying (it is always for me) and a mechanism where you can arm the next 1/4 turn without disengaging the screw is great
PS. when I say 1/4 of a turn, this is to to indicate the torsion of the wrist. Could be more, could be less
What goes away with the ratchet is the continuous clench/unclench action. While I don't normally have any other RSI-like issues, that movement just kills my wrist after 1 or 2 screws. I've got a ratchet screwdriver with an option to twist/bend it in the middle to get better leverage and the difference is amazing.
This is shown in action at this point in the video:
https://www.youtube.com/watch?v=2K5Gqp1cEcM&t=606s
In many ways, this mimics the function of a jewelers screwdriver:
[1] Literally free, I was given it at some conference.
It doesn't ratchet. It's basically just a bearing so you can push down on the top and the rest of the screwdriver can move freely—hard to explain I suppose.
If you know how to juice it, you can do amazing things with a bit driver, especially since you can put a lot of force to keep the bit set and still get it to turn.
People tend to draw analogues to ratcheting wrenches but the entire point of ratcheting wrenches is to avoid having to remove them from the bolt to spin it making it easier to use in tighter locations. No such benefit exists for screwdrivers due to their geometry.