Are journals biased towards more famous authors?
Correct me if I am wrong, but your previous experiences with publishing are only the one paper you published before, together with your former advisor? Then, you might lack the experience necessary to know about the typical mistakes that lead to a (desk) rejection. Your results may be very good, but this alone does not make a good paper. Being proficient in scientific writing takes time and requires practice. Your former advisor is a few steps ahead and you might not even have noticed some small corrections from her/his side that made publishing of the previous paper much more likely. Famous researchers usually are particularly good when it comes to presenting/writing about their results. They make it easy for the reviewers to like their work. Beginners often make it easy for the reviewers not to like their work. This does not result from bias, but from scientific writing skills. And the editor also needs convincing, so pay attention to your cover letter.
If you decide to go on alone, you might have to learn the lessons the hard way by facing a few rejections. An experienced person might be able to help.
And please stop making the mistake of calling the replies you get after peer review &quot;stupid&quot;. This is also a typical beginner's mistake. Sleep over the replies until you can look at them in a rational (not emotional) mood. In my experience, virtually all replies can be used to improve your work.