in camera HDR with electronic shutter

Sony a6600 can't do HDR-photo in electronic shutter mode. So in bright sun day in HDR-mode camera make 3 shoots, and shooting take some time, if something moving during shoots - it's blure. So shooting isn't as fast as HDR in smarthone.
Does exist cameras that support electronic shutter for HDR?

Cameras vary a lot, but it's fairly typical for the electronic shutter to take about 1/25s to traverse the frame. So, if that camera takes 3 sequential shots for HDR, they will take at least 3/25s to complete (and probably more than that). That will stop only very slow-moving objects.

If you want to stop very fast-moving objects, then you want the electronic shutter to traverse the frame in much less than 1/1000s. I have never heard of any ordinary cameras that will do that. You would need something like a video camera capable of taking thousands of frames per second. Such cameras exist, but tend to be very expensive and very specialised.

I suppose the question is not correct. HDR is possible using e-shutter. My cameras, specially the GX85 which is sticking on e-shutter, does it without problem.

The real question, I guess, is that HDR will usually use 3 or more burst shots to merge into a HDR output (if I get you right you were actually talking about in-camera HDR?). If there would be movement within the frame, it could result motion blur on the HDR output. E or M-shutter would be the same.

When I do exposure bracketing, e.g. 7 shots of 1 stop per shot, sometimes if there would be a pedestrian walking from acsidecto another, he might appear in different position of each frame. For some HDR software, I could get an output showing along tail of that person. For some smarter HDR software, I might get an output of minimal to no motion blur.

Any sort of stacking would have their limitation on application. Some scene are good for HDR and some not.

Not sure how phone works on this. Generally I am not happy with phone's IQ. YMMV.

I think that phones analyse multiple shots and eliminate movement when putting the HDR shot together. Some phones probably do HDR on every shot.

You probably already know that in-camera HDR is just exposure bracketing, followed by some kind of blending of the shots, followed by saving the image to the card. Some cameras have better blending algorithms than others. Both cell phones and cameras follow this same basic process.

Cameras are pretty slow for HDR in any shutter mode so we have to pick our scenes carefully. I don't have a fast stacked-sensor camera but it sure makes sense they would be nicer for HDR. With my slow-poke camera, I'll just take bracketed shots in the field and blend them at home on my computer using special HDR software (Photomatix Pro). This software has a module dedicated to reducing motion blur. It's still imperfect but a lot better than the in-camera algorithm.

Cell phones have a different approach. As soon as you start the camera app, it's constantly taking photos at 30? 60? more? frames/sec and storing them in a buffer. I'm not sure if even a fancy stacked-sensor camera can match that. When you tap the circle on a cell phone, the camera just grabs a bunch of photos from the buffer and processes those.

A guy named 'vas3k' wrote a truly excellent article on how cell phones use computational photography. The entire article is fun to read, but the real meat is the section "Stacking - 90% success of cell phone cameras".

On my older LG G6 cell phone, I had to turn on "HDR mode" to take an HDR shot. On my newer Pixel 6 Pro, HDR mode is just turned on all the time - every shot is an HDR shot.