Do "large business enterprises" use exclusively "customized encryption", or do they use the same encryption "consumer products" use? In my experience, it's the later. The biggest example is TLS: for instance, every business which uses Microsoft Office 365 relies on the same TLS used by "consumer products". The same applies to full disk encryption (BitLocker and/or LUKS), smart phones (large business do use smart phones, and they are the same smart phones everyone else uses), email, and so on.
As a personal example, the software we develop at work is used by "large business enterprises". When we added encryption to it, we didn't use "customized encryption"; we used standard TLS.