As someone who’s been in a similar position, there aren’t really any alternatives that don’t piss people off. reCAPTCHA is a pain to get past for a small number

As someone who’s been in a similar position, there aren’t really any alternatives that don’t piss people off. reCAPTCHA is a pain to get past for a small number of visitors, typically those using public proxies (e.g. Tor), but the majority just click a checkbox and are in. Cloudflare already has a lengthy complaint thread on their forums with people insisting they switch back to reCAPTCHA for this very reason.