While that is true, it also helps people new to a scientific area. I can read 3-5 papers on a topic and the first chapters of each will give me enough to understand the gist of the topic, the status quo.
It's a question of who you prioritize while writing a paper. Experts or the interested layman.
If you prioritize people who are already experts in the topic, you write little to no introduction, you get to the results quickly.
If you prioritize the "curious, interested layman" (or university students in their first years), a short introduction to a topic with references will provide enough information to understand the basics and the reader can continue reading the rest of the paper with enough context to understand why the topic is relevant.
The way I write a paper for "curious, interested layman" is different than the way I write for experts. It's hard to keep both in mind when writing.
Laymen, for example, might need some figures to help understand a topic that experts internalized years ago.
I prefer having occasional well-written review papers, meant for getting non-experts up to speed. Then the domain experts - who are often not experts at writing for laymen - can refer people to those review papers, possibly also with a history delta for what's new since the review.
There's an added difficulty of writing to "tangential experts". I've had papers in the past that were 'tweeners, between two related but different fields. Depending on the audience, background information was needed that may be tedious for the other group.
As far as I know, not really. Most journals require you to not submit to another journal until they've made a decision to reject so you can't submit to multiple. Even though they may have different intros, they’re presenting the same data.
It's a question of who you prioritize while writing a paper. Experts or the interested layman.
If you prioritize people who are already experts in the topic, you write little to no introduction, you get to the results quickly.
If you prioritize the "curious, interested layman" (or university students in their first years), a short introduction to a topic with references will provide enough information to understand the basics and the reader can continue reading the rest of the paper with enough context to understand why the topic is relevant.