Also notably, if you want every (or any given) climb to require a check, just establish complicating factors that make the climb an engaging challenge.
Because it gets back to the crux of the issue. Why can't the climb, itself, be the challenge without needing "other factors" to complicate it. Climbing is hard enough for a lot of people IRL, (yeah, yeah, I know--but the PCs are "heroes"

) so it can be challenging to PCs as well.
(Note: I am not saying the DC should be high, just that the climb becomes an obstacle. PCs with little or no modifier will find it potentially problematic. If you use the concept of failure by a certain amount equals a fall or slip or whatever, or maybe a natural 1 or something, it becomes an encounter worth playing out. Otherwise, it is just a narration:
DM: You managed to break open the small window. Now what?
Players: We throw our grappling hook through the window after making certain it is secure to the silk rope.
DM: Ok, after a couple tries you manage to get it through the window and it catches.
Players: We check it to make sure it feels secure and then climb up to the window if it is.
DM: Sure, it holds nicely. After about 10 minutes you manage to get everyone through the window, although the Firbolg was a bit of a squuze!
(Players laugh)
There is nothing wrong with this, of course, if that it what you want. I want it to be uncertain, so the PCs might need to find another way in.
Anyway, all I have to do as DM is decide some factor (height/distance, for example) is enough to warrant the call for a check. I don't need anything else, regardless of what others
believe the rules say.
It gets into the same spirit as was commented in another thread about the overabundance of magic in a Fantasy game. My preference is for a more mundane setting so magic is special--not mundane and blah, and climbing any significant distance (subject to each individual DM's discretion) is engaging.
I don't think many people would attempt to climb 80 feet up a knotted rope without some form of safety line, etc. Why? Because falling from such a height is stressful, and that makes it challenging.