There’s nothing inherently wrong with wearing jeans. Its not appropriate for some occasions just as slippers aren’t always the reccomended dress code.
Its can say something about the person wearing them. Let me portray. An electrician wearing jeans isn’t the same thing as a 18 kid in high school wearing jeans. The electrician is wearing the “rugged pants with pockets for his tools that’s actually makes work easier than other pants” whereas the Hs kid is trying to say “hey I’m different than where I come from” (talking about a yeshiva Hs kid) and I’m letting u all know. Its a status that he’s taking on and yes it does not come along with shteiging away and shmiras einayim.
There are definately exceptions to this rule and, older people wearing jeans isn’t making a statement like a teenager and young 20’s guy.
Its all about assosiation. Who do u assosiate urself with.