FDA is actually pretty collaborative with pharma companies. But also pharma companies’ business models aren’t entirely dependent on circumventing regulation and they aren’t openly combative with regulators.
Separately, yes, there are also instances of straight-up corruption. It's totally divorced from reality to suggest that collaboration is "only because" of corruption though.
NIH researchers (and their funders, US taxpayers) should be getting paid more in royalties from commercialized research.