I noticed that people read complex research over the obvious when they see a simple and clear abstract they don't read it why is this ?
This interpretation is completely wrong. Researchers don't select to read papers based on their complexity/simplicity.
Academics read papers primarily to learn about new methods/results which are relevant to their field of expertise, in order to stay up to date, improve their knowledge and hopefully contribute to their own research work eventually.
When selecting which papers to read, an experienced researcher usually pays attention to several criteria. A few of them are:
- First, how close the paper is related to their research, and consequently how interesting it is for them.
- Whether they already know the main contribution or not. If a paper has nothing new to teach them, there's no point reading it. Of course, original results are more likely to attract their attention.
- The reputation of the journal/conference, and possibly of the authors. This is important because a high reputation journal is more likely to publish interesting new work.
- The general "seriousness" of the work: if the paper doesn't prove their claims or contains obvious methodology errors, it's not worth it.
I'll speak only about math and CS, by main academic interests. In both of those fields, and perhaps others, the conclusions alone, which are probably what you see in the abstract, don't contain enough of the insights that make true understanding possible.
Science isn't about just facts and it doesn't proceed from fact to fact seamlessly. The arguments are often where the insights lie, and it is the insights that lead you to an understanding of what it is important to pursue and how to go about it.
In math, in particular, the methodology of the proof of a new theorem may be far more important than the statement of the theorem itself. There are some long standing conjectures in math that yearn to be settled. But when and if they are settled, it will be the how of it that matters, and for that, it is the details that matter.
Note also that some proportion of papers, even published papers, have errors. Specialists in an area may find results (in the abstract) somewhat implausible, and want to know why, requiring a deep dive into the methodology.