(Author here.) I have seen videos (not on trains) of one hybrid - a power-operated round sliding door, but with a physical lock on it, that hooks onto the door frame. So that would be one option.

I think the current iteration is fine though - the replacement of the confusing "lock button" with the physical handle, even if emulated, is comprehensible to most, I would think. The "the door is now locked" voiceover also helps reassure people. (Most people are just trying to lock the door and not "fuzz test" the lock handle...)