They litterally did that :)
And that can be controlled by your site's security level. Highest settings will show the JS page to all vistors, medium only shows it to likely bots.
You might be interested in a plugin to toggle the fingerprint protection: https://addons.mozilla.org/de/firefox/addon/toggle-resist-fi...
See also: https://news.ycombinator.com/item?id=34952279
But yeah, Cloudflare causes problems but I think it's partly the site owners that crank the security settings and bot protection to max.
If even with this the site doesn't load due my restrictive browser settings, I abandon the site and I don't look back (always are sites with tons of bloatware written behind blunders and infinite JS libraries).