No....Microsoft has a decades long relationship with Bethesda as well. They are just different sized deals.
Yes, they have a decades-long relationship.....because Bethesda was a 3rd party publisher who made games for Sony, Microsoft, and Nintendo.
MS wasn't publishing and funding their games like Sony and Insomniac. Insomniac is not a publisher. They weren't a major third party with gigantic multiplatform ips.
This is beyond "different sized deals". And if you can't understand then I can't help you.