The real issue is that the people who want to use the product and the people needed to make it usable aren't necessarily the same. Marketing generally caters for the former set of people, who are the people buying the product they want to sell. The grandparent post is more about open access to technical support documentation to make the product work afterwards. (In the worst case, you frequently end up with non-technical people having to act as a go-between between their vendor and local technical staff, especially in sufficiently-large organisations.)
Taking the SAML/SSO example of the grandparent post, the odds are that the only time the poster will hear of the product is when they're asked to do the integration to make logins work. It is unlikely that they will know or even care about what shiny features the product has, since they're not the expected user base. If there's simple documentation on integration methods freely available online, it's easy enough to read it in half an hour or so and figure out how feasible the setup is likely to be in your environment. Going down the demo/chat route is likely to take a good 1-2 hours minimum, and the likelihood is that much of that is wasted sitting through presentations for the product side. That's great for the actual customers, but not useful for the technical staff the customers brought along to make it work. If you're lucky, you might get to actually speak to technical staff that can explain the SAML/OIDC setup steps in call 1; often, you might well have to set up a second call to actually discuss the technical requirements if not more. With many such integrations, the time quickly adds up...
Taking the SAML/SSO example of the grandparent post, the odds are that the only time the poster will hear of the product is when they're asked to do the integration to make logins work. It is unlikely that they will know or even care about what shiny features the product has, since they're not the expected user base. If there's simple documentation on integration methods freely available online, it's easy enough to read it in half an hour or so and figure out how feasible the setup is likely to be in your environment. Going down the demo/chat route is likely to take a good 1-2 hours minimum, and the likelihood is that much of that is wasted sitting through presentations for the product side. That's great for the actual customers, but not useful for the technical staff the customers brought along to make it work. If you're lucky, you might get to actually speak to technical staff that can explain the SAML/OIDC setup steps in call 1; often, you might well have to set up a second call to actually discuss the technical requirements if not more. With many such integrations, the time quickly adds up...