> I've never had to do 18 joins to extract information in my career.

Really? You're not representing particularly complex entities with your data.

I work on a student information system. 18 joins isn't even weird. If I want a list of the active students, the building they're in, and their current grade level, that's a join of 8 tables right there. If I also want their class list, that's an additional 5 or 6. If you also want the primary teacher, add another 4. If you want secondary staff, that's another 5.

The whole system is only around 500 GB, but it's close to 2,000 tables. Part of the reason is tech debt archaic design from the vendor, but that's just as likely to reduce the number of tables as it is to increase them. The system uses a monolithic lookup table design, and some of the tables have over 300 columns. If they were to actually properly normalize the entire system to 3NF, I have no doubt that it would be in the hundreds of thousands of tables.