This is a tarpit. They've decided you're almost certainly a bot. If you're willing to solve the captchas for three minutes straight, they eventually might relent and let you in, or maybe not.
There is no good automated answer. Things bots do to abuse web pages should be made illegal and then jail (fine...) the people who set the abusive bots loose - but I suspect most abusive bots are foreign and so we can't do anything without sending in an army (obviously unacceptable)
Cognitive overload. There's days I'm just straight up tired and don't realize it until I'm at least one "please try again", page refresh, and endless traffic light game later that I'm probably in the tarpit and wonder why.
The weird thing is that I don't KNOW why. I use good ol' consumer Chrome, good ol' consumer MacOS, a consumer ISP, and my IP isn't in any kind of reputational blacklists that I'm aware of.