There’s a common belief that most jobs see people rewarded for presence rather than performance. That is, they’re encouraged to be on site from 9am to 5pm rather than being given free reign over their work schedules as long as key outcomes are met / exceeded.
In OSS vendor / product selection there’s a similar concept. Contracts are often awarded based on existence rather than excellence. When evaluating a product, if it’s able to do a majority of the functions in the long list of requirements then the box is ticked.
However, this doesn’t take into account that there are usually only a very small number of functions that any given customer’s OSS needs to perform at a very high level of efficiency. All the others are effectively just nice to have. That’s the 80/20 rule at work.
When guiding a customer through their vendor selections, I always take them through an exercise to identify the use-cases / functions that really matter. Then we ensure that the demos or proofs of concept focus closely on how excellent the OSS is at those most important factors.