Why is Lucifer so weak and less intimidating compared to every other demon and Angel (and entities really) we’ve seen in the Arrowverse?

 

Because ol’ Lucy (who is not “weak” by any means) isn't like the other demons we've seen in the Arrowverse, or any demon in general.

Lucifer Morningstar (The Devil) isn't about intimidation and fear as much as he is about manipulation and one-sided deals.

Most of the demons we've seen in the Arroverse (mainly LoT) have demonstrated the opposite. They mainly rely on power and might rather than their brains. There are exceptions of course.

I mean, think about all the stories you’ve heard of regular demons. How many of them are the stuff of nightmares? Often that’s not even the story, it’s just their appearance.

Now think about all you’ve heard about The Devil, Satan, Lucifer, whatever you wanna call him. How many of his stories are eerily similar to the stories from before? Probably not many, right?

That’s because, again, Lucifer is not like most demons. He likes to use his silver tongue and cunning mind to bait his victims into damning themselves wether they’re aware or not. He likes to pretend he’s your friend, play the long game if needed, and then backstab you in the worst way.

Most other demons look and do things that come straight out of the nightmares of the most twisted minds that you just want to forget. Lucifer is the kind of guy that is in those same nightmares, but you welcome him there (stated by Lucifer actor Tom Ellis himself, if I remember correctly, to be an intented character trait).

Lucifer isn’t meant to intimidate, he’s meant to be the best backstabber in the universe. To do that, he’s gotta look friendly.

Edit: since this has been getting increased engagement recently, I feel the need to clear some things up.

1. Read the question this answers carefully. It doesn't ask about Lucifer from the bible, it asked about a DC Comics character named Lucifer Morningstar from the Netflix show Lucifer. Lucifer crossed over with a small screen multiverse on the CW known as the Arrowverse. One of the shows included in this Arrowverse is DC's Legends of Tomorrow which has handled DC's version of demons and Hell as a part of its various stories circling us back to read the question carefully.
2. As far as the bible, I'm well aware that the devil was once an angel named Lucifer. Stop telling me what I do and don't know.
3. I don't care which theology you believe in, just know that I don't. The threat of eternal punishment in Hell might have worked to recruit you but it and other tactics have tried and failed to do the same for me. No, that doesn't mean I'm someone who promotes the devil or evil in general. I just don't believe in the same things that some of you might. Simple as that.