... I suggested something along those lines, but your comment smacks of a whole lot more know-how.
I worked in I/T for 40 years before retiring a couple years ago. Not in a server/admin capacity, but nevertheless having to constantly deal with and resolve problems, so it's second nature for me to look for the most effective solutions.
I think that almost none of this spam activity is innocent or harmless. I see it periodically on all of my regular sites, and this type of activity strikes me as probing for weakness. I believe almost all of it is backed by foreign governments or criminal organizations, and there's very likely to be serious consequences down the road if we're (collectively) not aggressive in countering this activity. And part of those defensive measures might very well require imposing some minor restrictions or inconveniences to the valid end-user community. I think most of us would understand and accept this, if it's explained along those lines. Unfortunate, but a necessary thing, given the state of the world today.
If I was a bit younger, I'd love to battle these idiots and try to grind them into the pavement.