Sad to hear that cloudflare is almost not working.
		
		
	 
Cloudflare helps a lot, but you have to put many hours of work into the config.  
I downloaded crawler IP json files from about 10 legitimate good crawlers and made a Cloudflare list from those IPs.  Then I made a security rule that says:
(
  not ip.src in $known_good_crawler_ip_addresses
  and (
    http.user_agent contains "GPTBot"
    or http.user_agent contains "ChatGPT-User"
    or http.user_agent contains "PerplexityBot"
    or http.user_agent contains "Perplexity-User"
    or http.user_agent contains "OAI-SearchBot"
    or http.user_agent contains "DuckDuckBot"
    or http.user_agent contains "DuckAssistBot"
    or http.user_agent contains "integralads"
    or http.user_agent contains "Criteo"
    or http.user_agent contains "AmazonAdBot"
    or http.user_agent contains "AppleBot"
    or http.user_agent contains "bingbot"
  )
)
Block the request.
About 75% of all requests with user-agents that match the above are forged.
Also turn on: 
Definitely automated traffic: Managed Challenge
and
Likely automated traffic: Managed Challenge
and 
Verified bots: Allow
and
Challenge all request ! from the US - (Brazil and Singapore are the two most offending, but the cumulative number of worldwide bad bot requests are astounding.  Only 1.16% of these requests can answer the Cloudflare challenge)
and 
build your own list of user-agents that should always be blocked.  This will take a ton of time, but it's worth it.
and
Rate shape the useful bots that make too many requests.  Some will respond well to a 429, others are just rude and won't.
However, NEVER block or rate shape Googlebot, else pay the price.  The "Verified bots: Allow" has a good list of Googlebots and will allow legit requests from Google and block forged Googlebot user-agents.  My point is just let Cloudflare manage Googlebot and don't do anything else.
This has reduced our "guests" from 20,000 to 6,000.  6,000 is only about 25% > the prebot storm.
If anyone wants my lists, I will be glad to share.  I hate bad bots.