I've never been to a conference with a junk submission accepted, or a junk presentation. Many conferences in my field reject submissions that are real but low-quality, even for a poster session. Talks are always competitive. I chaired a conference last year. We rejected some submissions that were uninteresting or poorly written. For most of those, the submission was read by two professors before rejecting it. We received no computer-generated submissions.
I sometimes get spammed or "invited" by suspiciously looking conferences. I never go to these. Why would anyone attend a conference that is lower-quality? There always are good conferences around. You have a choice.