This I believe is lowkey one of the core ways design broke at tech companies. There are other big ones, design (really product) is broke deeply, but once mockups became easy we stopped having discussions about information architecture and UX. We're talking about whether we think this looks nicer in blue or green. Happened before Figma, but Figma really grew it. The designers that tried to hold onto wireframes (or went to mockups, but tried to still have architecture discussions with them) fought an uphill battle—what were these guys even talking about? Even the other designers thought this.

Once mockups became easy, that little bit of vocational gate (as in gate-keeping) that was holding the wall for UX work went away. Execs and PMs could make decent looking rectangles, so designers became the people who could make especially nice looking rectangles. So you got a lot of product/UX designers that were much more visual designers. That matters, but the prior part was bigger in that the product processes and sprints often started to have little design in them at all. What was a two or three phase process was one, designer got requirements and made design—often they didn't even really get requirements before design. The design was the impetus for the requirements not the other way around.

This is what became standard: Leader would give something vague because they didn't have much idea or vision yet. They probably had something blue-sky-ish, meaning they had a bunch of ideas, which in amorphous abstract blue skies come together. Once those things appear side by side on paper/screen, they're off putting and contradicting. There are problems not just with how to fit the pieces, but with the pieces. The visual the designer provides triggers this. Designers being visual people can see a lot of that in their head beforehand, but won't be heard until they show "bad work." It's pretty common though to see the PM or the leader look at it and say it wasn't the vague requirements, it's that the designer didn't get it. Anyways, it's that design that then kicks off some assessment against reality. Then you have a little bit of a shot at real requirements starting to leak out.

Yes, though this has been a problem long before Figma or AI. Photoshop enabled pretty pictures of what a website / app / service might look like, and then these often became set in stone.

One solution is to keep all mockups / prototypes strictly grey scale using bare bones vectors until every stakeholder has weighed in / signed off.