I see your maths here but Cloudflare hits include any assets, images, and so on so one page views fans out potentially dozens of hits. Cloudflare also includes all bots and non-human hits.
Assuming $0.50 net CPM on one AdSense unit per page view, that would be $70k monthly/$840k yearly revenue. And since operating cost is $100, that's all profit. I'm no AdSense expert but I believe this would be super conservative, maybe an expert could chime in with higher realistic numbers. Even if you don't like advertising there are other ways you could earn money with a site like SteamDB.
Why do you think google analytics is more right than cloudflare? Adblock can block GA, but it can't block cloudflare