Is it true that manga is horrible compared to the light novels?

I don't like LNs (I rather read a regular novel) but I have to say that the source material is usually better. It's not really a matter of LN vs manga (vs anime). All of them have weaknesses and strengths. The problem is that most (bad)adaptations just copy most of the stuff (especially dialogue) and fail to use the strengths of their medium.

For example a LN have to describe a lot of stuff, because well how else do we know what's happening? Anime and manga (in a lesser amount) don't have to describe everything, since they can just show it to us. The problem is that bad adaptations don't use that. They just copy the dialogue and in the middle of a scene we suddenly get a boring explanation (that's just stating the obvious) of something we've just seen The other way around it's also a problem. An anime/manga for example doesn't have to describe a characters feelings because they can just show it on the characters face, but it's very bad when a LN just copies the dialogue without telling us how the character feels.

Though one of the main reasons that the source material is better, is that its adaptation only gets a certain amount of chapters/episodes. The original source didn't have that problem. So as a result the adaptation has to cut/skip stuff, making stuff feel rushed and characters lacking depth.

I also want to add one thing about why certain adaptations, especially LN, look extra terrible, they're fan translations (unless you can read Japanese of course). It's nice and all that certain people do that for others. But most of them aren't exactly professional writers, so the flow of the dialogue can be really awkward.

Obviously not. If I have to comment on this manga are infinitely better and simply because they generate higher revenues. What is better in expressing ideas - a pictured story or a worded story? Light novels are pretty much novels with anime/manga themes.