Not wanting to excuse Google here, but I wonder if a certain kind of moat can build by itself if a company is big and well-known enough. E.g. many websites hav

Not wanting to excuse Google here, but I wonder if a certain kind of moat can build by itself if a company is big and well-known enough. E.g. many websites have restrictive robots.txt files or other anti-bot and anti-scraping measures in place - however, I'll claim that most sites will make a specific exception for Googlebot. Not because Google pays them or anything, but because it's common knowledge among web developers that search engine bots have to be let through. The problem is that there is no public registry for search engines, so developers just go by the engines they know and deem most important - and that's primarily Google. If they feel generous, they'll add few of the other biggest players to the list as well, such as Bing or DDG, but they for sure won't add some obscure startup they never heard of. The effect is that anyone trying to create a new search engine automatically will have a harder time creating an index of the same quality as Google's, even if they had access to the exact same hardware, algorithms and expertise as Google. So in effect, the quasi-monopoly perpetuates itself, exactly because everyone else is acknowledging it and adjusting their own behaviour towards it.