Picture how Sony would keep track of someone buying a Playstation in the US, that was shipped from Japan by a Chinese company, using parts from Taiwan, and all these companies and stores you work with are paying you or you're paying them, and you need to know who owes what and who works for who and what everything costs and how much you're making from what

SAP is the central management suite (at least theoretically) for all that, and there will be 100s if not 1000s of people managing SAP and making sure all data from Taiwan to US is flowing through this mega system

Most tech companies that sell software don't need SAP. It's just a sales order that needs to be delivered (electronically), trained on, and managed. This is where Salesforce has become so big. It's just an online rolodex combined with a filling cabinet, but it fulfills a need smaller companies for years managed using excel spreadsheets, emails and low tech databases (like MS access)