Not really, the whole industry knows Taboola and Outbrain are the lowest tier, barely above scammy affiliate links. There are of course worse networks like RevContent but nobody is mistaking Taboola for anything but shady.
Taboola and Outbrain at least have manual reviewers attempting to uphold a certain standard for content, though there is a ton of room for improvement. I've never noticed a lot of suspect traffic coming from these two, which is in stark contrast to networks like content.ad or adblade. Of course, Outbrain/Taboola don't compare to the big networks, but I've experienced a good balance of affordable and reasonable quality traffic, though this isn't always the case, as costs/quality can be quite variable over time.