I am not sure if I can find this but remember a story about a load of presumably single ladies who were asked if they would close their Insta for a marriageable man.
Most chose Insta so this is a big deal.
90 days suggests a VWP visit not a B2 and the VWP can not be extended.
Never heard of anyone being refused an immigrant visa and not being given a reason.
https://www.visajourney.com/forums/forum/130-adjustment-of-status-from-work-student-amp-tourist-visas/
Head over to the Adjustment forum there is a Guide there.