Abandonment, a real risk that affects almost every business that depends on software. The original vendor may abandon a product, go out of business, or increase license fees or other terms. Developers paid to write custom software move on or stop returning phone calls.
Larger organizations may have plans to mitigate risk, and the resources to deal with it. Smaller organizations can get surprised, suddenly finding themselves unable to get support. I have seen versions of this over and over, and I built my own consulting business maintaining and upgrading (and sometimes replacing) legacy software system and obsolete infrastructure.
You can see complaints online about the huge number of companies still running PHP 4 or 5, or ancient versions of WordPress, or Python 2. You can still find old Compaq servers in closets, antique networking gear, Microsoft Access databases held together with tape. Every one of those represents an opportunity.
