The way this article described Salesforce makes it sound like generic database frontend software, like a more powerful, complex, and customizable Airtable. I'd love to read a comparison of the two if anyone has used both.
You can do most things you can do on Salesforce with generic software, but the know-how is explicit on Salesforce (think Open Source vs Microsoft). There´s also the backing, support, etc., and them being the original SAAS which I guess is the BIG part (that must have been some pretty huge savings back then).
There´s a team of Salesforce devs working next to where I do, and it does look very much like any other database frontend software, but with the sales vertical. Instead of choosing Java or .NET or whatever, they go Salesforce.