There absolutely will be many, many old systems that predate and don’t use SQL there. Anyone denying this has zero idea about how many extremely old legacy systems are still in use in big corporations and governments. Hell I’ve done work for companies with revenue in the billions who were still using a legacy Access database program that they didn’t have the code for, nor any documentation, so trying to automate data imports was an absolute nightmare - but they insisted on not replacing it because “that’s the system we know and it works”.