This depends on the user ISP, especially if they are in a country where gambling is prohibited. Razed has been running very smoothly so far, with no issues as Cloudflare verification only appears once.
I don’t think this has anything to do with your ISP. If your ISP was blocking access to Razed then you wouldn’t be able to open it at all, you wouldn’t even get to the CloudFlare verification page.
You would usually experience this if CloudFlare detects that you are making multiple requests in a short period (DDos protection).
But since all users are experiencing this then it’s most likely that Razed team made some changes to their CloudFlare security settings.
But as you said, there is nothing to worry about.
I agree with what you said, this has nothing to do with the ISP. It’s more about verifying user behavior, such as IP addresses, VPN usage, unusual traffic, and so on. It’s nothing to worry about, because if there’s no issue, users can access the site quickly.
And it’s not just razed.com, but the majority of popular casino sites also use a cloudflare-based verification system. This appears to be a security standard implemented by almost all major platforms to maintain the stability and security of their sites.