Vendor lock-in is usually framed as a risk to manage. In practice most organizations accept it passively and only discover the cost when it is too late to renegotiate from a position of strength.

The decision that creates lock-in is rarely labeled as such. It is a procurement choice that optimizes for implementation speed, or a renewal that is easier than running a new tender. The lock-in is just the accumulation of those choices, each reasonable at the time.