Why is Plagiarism so Much in the Academic World?

Why is Plagiarism so Much in the Academic World?
When a professor tore up my work in a journal, they escaped without penalty. How can we expect academic originality from students if we do not uphold it?
I always consider plagiarism mainly done by some lazy students and overly ambitious politicians. But since finding plagiarism from my own work, I see it as more pervasive.
Three years ago, I read about the latest research in my field, when I found a sentence that was quite familiar. Rereading the entire paragraph, I realized these were my words - I had published them on an academic blog two years earlier.
It turns out that the 301-word cut of defeat in the article was copied verbatim, only slightly changed, but several other parts in the article used my argument without credit. There are no footnotes or references that acknowledge my work.

Students cheat in more creative ways: how can academics stop them?
I was stunned because I didn't believe that a professor full of high global standing - a respected leader in their field - would do this. I am also honored because, of course, imitation is a form of praise. Mostly I'm angry that my important article was recently rejected, but here are other people who made my half-baked blog published under their name. But I am also worried, because now I have to prove the authenticity of my work. Even now, I am still afraid of retribution if I ever publicize the incident; I avoided my institution while a plagiarist recently visited.
As a first step, of course I consulted the internet, and, oddly enough, I found many sources of advice for plagiarism - but not for those who have plagiarized. This includes suggestions that make no sense to academics, such as "the five legal proving strategies when destined for plagiarism".

I decided to bring this case to the high-level economic journal in question. The editors handle it very professionally. They chased the writer for several months, and finally got a lame response: plagiarists admitted that they "did (inadvertently) depend heavily" on my work, and suggested that publishers revise the online version of the article by repeating the words. paragraphs meant by their own words. I insist 303 words are set as block excerpts, carried out by journals. The editors of international journals also print a corrigendum in the next issue.
But not once in the process did the writer or editor admit that the problem was, in fact, plagiarism. Retraction should have been discussed.
Even though this happened three years ago, something still tickles: the plagiarist escapes without penalty. We try to instill a deep respect for our students in source and reference material. But if an established academic tries to dismiss someone else's work as their own, and is caught, is a receding quote the only consequence?
Of course anyone who reads the article will now find my work quoted. Corrigendum will probably warn some readers about the next print problem for something suspicious, and the editorial board can put question marks on certain colleagues. But I wonder whether such violations of academic integrity usually have minimal consequences.
I also realized I was very lucky: I actually found a violation, was able to prove it, and suffered minimal damage because a blog entry, rather than an entire book or paper, was used. From other senior academics I've heard far worse cases. One tells of how, as members of the editorial board, they presented an article by a professor, which they recognized as work stolen from a PhD student. The student's fortune is that the editor has seen them present this work at a conference.
Perhaps the order of academic power is a contributing factor. Both cases involved senior academics who dismantled the less well-known baccalaureate. I doubt they will plagiarize the work of other professors without thinking, for fear of retribution and loss of reputation.
After talking with colleagues for years, I had the impression that the use of other people's ideas without permission is something that is widely known and very hated, but rarely discussed or openly problematic. In academia, praise for original analysis must be the key to success, and we must be open to recognizing the contributions of others.
A simple plagiarism check must be done for respectable journals - as well as for student journals. A few minutes running the software can prevent this whole mess, because my article is easy to find on the internet. However, I am not sure about how to counter the more dangerous use of junior intellectual power, such as with professors who submit student articles, or with those who use assistants to do heavy work without acknowledging their work.
Perhaps the most practical advice I can give is to always self-publish: even the most abusive work papers, discussion papers, or blogs thrown on the internet are proof that the idea is yours first.