The cloudflare customers who benefit from the bot protection do not see it as an attack. On the contrary, they see it as a defense from an attack.
Also, it’s quite disingenuous to label cloudflare as only slowing things down. One of their primary functions is a global CDN/cache which significantly speeds up otherwise bandwidth constrained sites.
Man in the middle attack typically implies an unwanted third party, which in this case is not true since Cloudfare is explicitly and voluntarily trusted by the host server. It wouldn't be all that different if the web server had the browserintegrity checks developed themselves.
This is precisely what Cloudflare is doing to end users - causing problems like OP (and myriad others) experience by slowing down and/or blocking major chunks of the internet
I understand that it may be viewed as unpleasant, but ultimately if you install a proxy on your end that the server does not like (say an ad-blocker), I don't think it would be fair for the server to say its suffering a MITM attack. Likewise, even if the client is not happy with the third party the server is requesting, it still doesn't make sense to call it a MITM, IMO.
Also, it’s quite disingenuous to label cloudflare as only slowing things down. One of their primary functions is a global CDN/cache which significantly speeds up otherwise bandwidth constrained sites.