What is NOT Vendor Lock-In
It is summed up in the following statement:
“If Coke stops satisfying me for even a moment, I’ll switch“
But to what are you going to switch? If you have to switch software, then you are lost. You want to switch vendors but keep the software.
To fire your vendor, you need to co-own your software.
To co-own your software you need a solid FOSS license.