Literally everything you do with memory and disks can also be reduced to CRUD, but that is an extreme example to show my point: a DB does a lot more. A well written DB, in this case a good RDBMS, gives you stronger guarantees that data is saved and accessed in certain ways. That by itself is worth using a better one that gives you better guarantees.
But they also provide stronger typing and checking of the data. They provide a programming language neutral way to access the data quickly and efficiently. They index data to make queries on it faster. They do much of this automatically so you think it's all simple CRUD operations, but they also provide ways to explain what they're doing if it isn't working as expected. I can count the number of programs (not DBs) on my hand that I know of that can explain themselves accurately without needing a debugger.
Edit: I don't mean to be annoying. Most people on HN knew this and I'm not assuming you didn't, but while most people just use RDBMS for simple CRUD operations they're losing out on the power that these databases have been designed with.
But they also provide stronger typing and checking of the data. They provide a programming language neutral way to access the data quickly and efficiently. They index data to make queries on it faster. They do much of this automatically so you think it's all simple CRUD operations, but they also provide ways to explain what they're doing if it isn't working as expected. I can count the number of programs (not DBs) on my hand that I know of that can explain themselves accurately without needing a debugger.
Edit: I don't mean to be annoying. Most people on HN knew this and I'm not assuming you didn't, but while most people just use RDBMS for simple CRUD operations they're losing out on the power that these databases have been designed with.