Sounds like the Pareto Principle at play: 80% of the product is created with 20% of the effort. It is getting the next 19%, then 0.9%, then 0.09%, and so on, that is the challenge.
Many years ago I built a search engine for a very big discussion board website, which had hundreds of millions of messages. Keep in mind back then a powerful server had 2GB of RAM and a pretty slow CPU and HDD, so it had to be distributed across multiple shards to work fast enough, and there was no Elastic Search back then, so it really was hard work, plus getting the ranking and quality tuned was a huge effort. Of course when we launched it people responded with "I don't get what the big deal is, why can't you just run a SELECT WHERE LIKE query and get it over with over the weekend?". It was hurtful at first but then I realized how ignorant the person making such a statement is about the problem.