> This is a weird assumption. What's preventing a backend system from saying "Hey, we think you're a bot. Here's an alternative way to contact us."
Not a weird assumption, but a necessary assumption based on considerations of scale.
A small-scale website that doesn't receive too much spam attempt can manually classify spam by human agents. A medium-scale website can have CAPTCHA to let through some visitors and the rest goes to human verification. You appear to be in this bucket. When the scale is huge, no other alternative way to contact exists. CAPTCHA becomes your only tool.
In other words, CAPTCHA is only necessary because of scale; what do you think the first A stands for? But because of scale, alternate ways stop working.
Not a weird assumption, but a necessary assumption based on considerations of scale.
A small-scale website that doesn't receive too much spam attempt can manually classify spam by human agents. A medium-scale website can have CAPTCHA to let through some visitors and the rest goes to human verification. You appear to be in this bucket. When the scale is huge, no other alternative way to contact exists. CAPTCHA becomes your only tool.
In other words, CAPTCHA is only necessary because of scale; what do you think the first A stands for? But because of scale, alternate ways stop working.