You can build another shitty clone to Google search cheaply. Elasticsearch plus some bots crawling fed off a queue can give you an approximation of Google that is useful to a lot of people (albeit not cheap to keep running). I cannot build even a shitty fascimile of an electrical grid cheaply because I need permits for digging, to deal with existing infrastructure, and I need serious capital (an order of magnitude more, at least) to build and maintain some sort of generation capability.
I can demo an alternative to Google Search in a weekend. I can throw comparatively small amounts of money to improve it (e.g. add more sites) such that it is extremely useful to find sites that I designate to have crawled (and it's not difficult to crawl the top N sites). My algorithms will be worse, my crawler less efficient, I probably will ignore javascript, my database will be larger than it needs to be, but none of that matters to an end user who wants to type in some text and get a list of results. My product would be worse in every way something can be worse, yet still satisfy the needs for a sizeable majority of users. It can scale out in known ways (way more expensive than google does it, slower than google does it, etc) by largely paying salary and hosting costs.
I absolutely cannot decide I want to install some poles to run electricity through a town without permits, insurance, inspections, and a ton of capital. I can't decide I want to build my own power plant and sell energy to my new grid without jumping through a lot of hoops, some of those hoops only a mountain range of cash can solve (compared to the merely large pile you'd need to run a credible regional alternative to google search for some segment of the population).
What else would you call DuckDuckGo? Easy is relative. It is relatively easy to build a search engine that can service a user's requests (possibly less useful absolutely, but within the realm of service) compared to building an electric grid and power plant that can handle a large number of user's power needs. One of these can be done with technical skill to get to an MVP in a weekend. The other requires a hundreds of millions of dollars worth of equipment, legal fees, permits, and engineering time before you even get started digging.
