Does anyone here take ArXiv seriously

ArXiv includes quite a lot of unreviewed papers. Unless people are actually looking more deeply into the state of a particular paper, you can't assume that it's correct or meaningful.

ArXiv is not a bad service at all, but I think a lot of people think that everything there is more reliable than it actually is.

You seem to have completely misunderstood the purpose of arxiv, which is to be a preprint server. It is not a place to publish results (in the sense that it is the final place for a paper's results) and there should be no general expectation that anything there has been reviewed. The purpose is to be lightly moderated for the purposes of circulating papers quickly for things like feedback before peer review and to have a reference on when results were completed (not completed the publication process, which is different) for the sake of establishing chronology.

If you were reading papers in a serious way you should have already been tipped off by the fact that references in any credibly reviewed paper will rarely and only in exceptional circumstances cite an arxiv paper for these reasons.

If you were using it as a sole place to do research you have made a grave mistake and you should educate yourself on where credible work is published for whatever your area of interest is. Those typically cost exploitative amounts of money and is a separate problem, but isn't something you can just wish away because you stumbled on arxiv without understanding what it is.

As usual, there's a relevant xkcd [0] - the only thing that arxiv tells you is that they went through the trouble of preparing a pdf. But if we have to choose between arxiv and Elsevier, I strongly prefer the former.

[0] https://xkcd.com/2304/