Before submitting to any indy, always take a look at what they’re publishing. As a writer and someone who’s likely worked with an editor, you can probably extrapolate the quality of a book by reading just a few pages, and the first pages are the ones a writer polishes the most.
This is something (general) you should do with any and every publisher, not just indies. Read the books the house publishes. Do it with agents, too (might be even more important, given how critical fit can be): read the books they represent. Look for genre, common shared tropes within genre, stylistic quirks, POV choices. Not
just quality. Find somewhere your book fits.
Quality's going to be subjective, though I agree about the lack of any obvious editing in those samples. I found two blatant typos on the first page of the second sample, for example. Even good writers occasionally leave a typo in there. You'd hope not on the first page, but then that's why editing matters. I'm not going to make any comment on the quality of those examples except to say it's pretty obvious Oftomes isn't pulling their end.
People get sucked in by bad publishers, too. This is why this forum can be so heartbreaking sometimes. Of course authors want their books out there, there's a natural tendency to rush things, and it's hard to say 'no' when an offer is on the table. Or you're into production. Thus the importance of reading and researching beforehand. Don't just check here. We may not have a thread. Learn the signs, find the books, read the books.
Another good habit to get into: never assume your editor will find everything. Not-so-great editors exist and by nature most authors will be blind to their own mistakes. No editor is perfect, either. Editors get rushed to meet deadlines, they take on too much work, they have family crises. Send in the best material you can--the cleaner, the better. Never assume someone else will vet your words before they're in print. You're responsible for everything you write.