While this hasn’t traditionally fallen under the supply path-optimization umbrella, wrapper duplication also wastes an awful lot of the work done in the name of efficiency. Despite being the most direct possible path, your demand-side platforms are still bidding on the same inventory believing that it’s unique. The Global Placement ID (aka GPID) can be used to identify duplicative paths to the same piece of inventory.
Why are you OK with SSPs sending multiple requests for the same inventory as long as there's plausible deniability when the duplication has been obfuscated by the header bidder? That is just bad business and is pure waste from a sustainability perspective—and you don’t need an emissions calculator to tell you that.
Made for advertising
Determining what is or is not made for advertising—often spammy, clickbait or low-quality websites—is a mixing board, not a light switch. Brands will have different tolerances. That is OK. What is not OK is (a) not doing basic quality checks of inventory, (b) having the conversation to figure out where that line is for a brand, and (c) not bothering to understand the perverse incentives created by the media metrics in the bonus malus clauses of contracts.
According to Jounce Media’s State of MFA report, as of September 2023 MFA is still taking up 20% of the bidstream. MFA websites use a TON of energy by cramming content with ads and not following simple best practices, which results in ads being seen on a page that makes consumers angry while frantically searching for the close button.