How do I remove the 'slideshow' bar and keep the menu in Photos app on iPhone 13?

It seems not to be possible to hide the filmstrip with the thumbnails without hiding the control buttons as well. We have to tap the photo to hide the film strip overlay with the thumbnails, but that will hide the controls as well. The Photos user guide does not even mention this filmstrip. View photos and videos on iPhone - Apple Support

If the image has been taken in landscape mode we can simply turn the iPhone into portrait orientation. Then the filmstrip with the thumbnails will be below the photo, and we we can still access the buttons.

For example:

wednesdaytgw wrote: … as I'm scrolling through photos, the view changes from a white background with the menu and annoying bar of photos at the bottom, to all black, requiring more taps to get to "delete"

is there a special way of scrolling that will keep the menu?

I, too, get irritated by the filmstrip and buttons showing up when I just want to scroll through pictures! If I can slide your finger perfectly horizontally, then the scroll is smooth and the pictures are full screen and lovely. But a tap brings up the filmstrip, and I haven't exactly figured out how to convince the phone that I'm sliding not tapping. I think it's mostly keeping my finger down in the scroll long enough for the phone to know I'm not tapping.

I think the answer to your question is that you have to be extra careful not to let Photos think that you are tapping rather than scrolling. And then bite your tongue to avoid offending others in the room when it slips up.