I very much disagree with your premise
* one does not need $200-300B ARR to run a search engine; and merely making a ton of money does not mean that the way that one has been making that money will continue forever
* using Kagi, one realizes how much the web has been perverted, in my opinion, by the obsession with the ad model; there are many nice, novel things that Kagi could introduce which would reduce ad revenue for a company like Google, but would be useful and novel for Kagi without loss in revenue (on the contrary — could help); ie google is incentivized to keep people on the site through various irritating means; a search engine that isn’t distracting and gives me what I want — I would be more than glad to pay for (and already do pay Kagi $10/month)
Other thoughts:
* Supposing $10/month (honestly I would consider $20) with 100M paying users; that is $1B MRR which is not bad at all and is more than plenty for a meaningfully sized team with meaningful salaries.
* Just like how lowered energy prices during and after the Industrial Revolution made manufacturing at scale feasible, the incredible amount of high quality OSS and infrastructure these days is making it increasingly feasible to do things Google did 20 years ago — something unthinkable for even the best engineers of that era. Not to mention the relative ease of collecting capital with payment services (let alone VCs, etc.) today — even with a looming recession factored in.