I don't think self publishing should be seen as negative, there should be no stigma attached to it.
I think there is less of a stigma than there once was, but it's still there. It's inevitable when there's no gatekeeper and a reader has to sift through shoddily written and published books to find the professional-quality ones. Many of us don't bother and stick with trade-published works, unless a self-published author comes highly recommended. Even so, there's a lot of chaff, but it's much easier to find these books.
There's also a problem of visibility or searchability (especially for new writers). Even if they have the money to spring for targeted advertising, as Filigree said, self published writers don't get the same amount of review or promotion at the distribution level, and this is what brings many books to the attention of readers.
An acquaintance who is very successful with her self published fantasy series suggests that people have some experience with publishing before they try it (he first novel was published with a small press, and she decided to go it alone after, when sales weren't that great), because they'll understand a bit more about things like how to work with editors and so on, and a bit more about how books are promoted and marketed. Also, it's a reality check to be sure you're really writing at a "publishable" level. Many self published writers aren't quite there yet, and their repeated rejections have been for that reason, not necessarily because their work is excellent but falls through the gaps.
I understand why someone might want an agent and go the traditional publishing route however if the only thing stopping them from self publishing because they think it's "lesser than"
The thing that's stopped me from self publishing is the up-front money required from the author to do it well. It's a big gamble, and many self published authors who are successes become so after writing several books and publishing them on their own dime. This is a big financial commitment for something that doesn't pan out. Also, I have little idea what kind of editing my work might need--developmental, structural, polishing, copyediting, or more than one of the above--to get it up to snuff.
Also, not everyone has the time, temperament or background in business to market their own book effectively. There's also the thing where self publishing requires a pretty high rate of output. Another person I know who is somewhat successful, as in selling hundreds to a thousand or so copies per book, with his self publishing endeavor (it's an urban fantasy series) brings out a new book of around 60k words every couple of months. This is shorter than typical trade-published fantasy, even urban, but it's still a really high rate of output for someone who may have a day job. I don't write that fast, and readers of my preferred subgenre expects much longer word counts.
Yes, some PoC writers can and do self publish, but not all can, any more than all White writers can. Even if self publishing is a great option for many people, the fact that more PoC authors have no option
but to self publish is a real problem.
It's not for everyone, and the problems aren't just with a relative lack of prestige.