alt Hacker NewsIsn't this the same sort of cost CloudFlare and anime catgirls are making us pay daily? Only enough to deter bots, or "a few seconds processing."
I take your point that one extra click/interaction required for screen readers only is objectively more friction, but it's only by exploring these technologies instead of dismissing them that we'll arrive at UX solutions truly work for people of all stripes (and ideally, not for bots, scrapers, and the like). I think if you're applying a tool like this you already have very different priorities than fueling Google.
As soon as you need to put a "decode" button for accessibility functions to work, you're effectively posting the key along with the cipher. It's self-defeating because any tool that supports screen readers will also support scraping. It's a fool's errand.