You dont need fade-in / fade-out effects for rate limiting. Bots are obviously get to see images instantly once they're returned by the server as they dont need

You dont need fade-in / fade-out effects for rate limiting. Bots are obviously get to see images instantly once they're returned by the server as they dont need to wait for fade-in to complete. Because bots API is injected into browser internals instead. If rate limiting is needed there is always CloudFlare way where you're literally show user "wait" and refresh page a bit later. This is annoying, but nowhere as much as reCaptcha fading is.