Y-Combinator backed company which does something along the lines of what you describe: https://onetool.co/home/
"Keep your competition out! onetool accepts a limited number of partners for each service and pricing-tier. Most of your competition will not be onboard if you are."
Read as, we'll only support a limited number of vendors who approach us first, regardless of which the best solutions are.
More likely, they will only recommend the vendors they get the biggest cuts from. As a user this is no use.
Interesting that their social proof lists a bunch of silicon valley companies that are probably about the least likely to have the issues I described.