And the beat goes on. If they are your travel photos for you enjoyment - you can do whatever you want.
If you are trying to represent "photoshopped" photos as the "truth." then there is a problem as they are not a the truth.
What is the difference between graphic arts and photography? A photograph is a recording of a volume of space at an instant of time (or more precisely over a segment of time). To insure that is the reason the content Authenticity Initiative started.
https://contentauthenticity.org
A significantly altered photo (sky replaced, people added/deleted, etc.) qualifies nicely as graphics arts. For example much of Andy Warhol's work is graphic arts.
A camera club which I am an "outside judge" for has multiple categories. One is documentary and street. There was a lot of discussion on the guidelines and standards on this topic. It got heated from time to time. I threw some fuel on the fire when I pushed for a rule that forbid cropping as a standard for that category. Henri Cartier-Bression and Gary Winogrand believed the image should be composed in the viewfinder not in the darkroom so there is precedent for such a criteria. I did that to just stir discussion as it would be very difficult (but not impossible) to determine if an image were cropped.
It has a specific set of rules. Those rules state that only global adjustments are permitted along with local exposure control, e.g., dodging and burning. That is one can change exposure, contrast, sharpen, apply curves and dodge and burn. However, all those edits have to be applied globally with the exception of dodging and burning. When that category was introduced, we got a lot of entries to the monthly competition that did not quite understand and we ended up disqualifying entries until the rules were understood.
BTW most of these types of edits you refer to are easy to sport. Sky replacement is probably the easiest. The issue with sky replacement is light direction. Light direction is encoded in just about every element in a photo - including in the sky. I have yet to see a sky replacement that is synergistic with the lighting in the picture elements. Once you know what you are looking for you can't unsee it.
So I see it as a continuum, photographic art to graphic arts. The problem is not that AI fueled local manipulation is bad or good. The issue is your image is presented honestly and at what point on that continuum does an image cross from a photograph to a piece of digital art based on a photograph to a piece of graphics arts based on a photograph ah la Andy Warhol.
If images are for personal use - have at it and replace people, outhouses and skies to the hearts content. It is when the altered photographs are passed off as "straight photography" or a recording in space and time has been significantly altered without full disclosure that graphic arts techniques have been use.