It is a matter of taste, skill and target audience, among other things.
If you know a bit python already, you are of course aware, that the py in renpy stands for python.
I saw vn in renpy, unity, rpg maker (of all things), custom engines, visionaire, twine and probably other stuff that did not bother to identify the engine used. The requirement for basic vn style storytelling is just not that big, so you can bend just about any engine to do that. Show pictures, show text, rinse, repeat. Maybe some scripting to do branching.
It is the things you wanna do beyond that, if any, that would favor one engine over the other. And of course, licensing and stuff. Unity currently is in bad favor among the gaming comunity. And I do not understand the people making vn in rpgmaker. Yeah, that is possible, but that thingie is catered to making characters run around and do fights. Ok, ok, it has maybe benefits, in certain circumstances or for certain story telling techniques. Also, this godot seems to be unpopular for vn - so far. Maybe unitys disgrace will change that.
But renpy gives you all those nifty features like rollback and saving. Of course, if you do not want to have rollback, you have to disable it (can be done). And I guess sandbox games have to do some more python to get their buttons working, but I saw some pretty advanced stuff done there, that might have been easier in another engine.
I can not speak much about visual novel maker. There are some games here on itch that tag that, but not very many. Either it is not very popular with the publishers on itch, or it just does not get tagged. It is not even on the list below. I guess it is unpopular here, because it is a paid product and most of the other stuff you can use for free in certain situations.
https://itch.io/game-development/engines
This is of course all from a gamer's perspective. I would tend to use renpy because you already know python or to that visual novel maker, if you already have a license and are familiar with it.