Having security check before users can access debian.org (www.d.o), in this case by reCAPTCHA, can also present problem: if a user can't pass the check, she can quickly leave www.d.o and she might tell others to avoid Debian due to difficulty to access www.d.o, thus we lose her.Have we a problem that users can't reach the Debian websites on www.d.o? Not as far I know.
For someone who explore www.d.o just for if Debian suit her, giving her only temporary access to www.d.o's web property can affect her: she might to answer reCAPTCHA again if the grace period to access www.d.o is up.
BTW, what is web property in the case above?
In case of Capezio, the site is on #1 if we googled Capezio. I haven't checked the site yet, but the site maybe well organized.Have we to mind that SEO is a critical thing for Debian. I don't think so. Yes we can improve some things SEO related, but it's not bad as hell. And SEO is related how you organize the websites, not related to CDN.
Performance and security is crucial to SEO. Search engines tend to rank higher for well-performant and secure websites.
Consider the case when someone in his office/shared network tried to access websites which have reCAPTCHA challenge enabled. When he encountered the challenge page, he asked his network administrator to perform a scan across his entire network looking for infected and/or misconfigured devices. If the network administrator fulfill his request, there will be presumably long downtime due to device scanning. If not, he will always to complete reCAPTCHA everytime he access the website.
There is also consequence of this feature: If the user browse a
website under Chrome and she encountered reCAPTCHA challenge, she
may migrated to Firefox just to get Privacy
Pass Extension in order to get rid of the challenge. If all
Chrome/Chromium users do the same, Firefox will be the most used
browser, thanks to Cloudflare's endorsement.