Sinatra and ‘lounge music’ made a big comeback in the nineties with younger people then in their early twenties, that would Gen X, not the boomers.
Gen X thought the late 50s and early 60s were interesting 30 years later.
The Bond revival was also in full swing with that age group too, which is why we got Bashir’s Bond hijinks combined with lounge culture.
James Darren was the real deal as a lounge singer. His career was trending upwards again during the show because of the lounge culture trend.
I’m also going to make a pitch for holodeck/holosuite episodes. I would absolutely argue that in the 90s they weren’t filler at all.
They aren’t as interesting now because they are too close to technology that we use everyday. That’s likely why we aren’t seeing Holodeck episodes in the same way in the new era.
While virtual reality, and shared role playing games are deeply established now through massively multiplayer games and discord, Star Trek in the 90s was actually doing its s job as a science fiction show imagining what people could do with VR and what could go wrong.
Taking it back to TOS, a shore leave planet that turned out to have interactive holographic characters and an operating system gone wrong wasn’t a trope, it was an entirely new concept. More, it built on the psychological thriller concept of imaginary things becoming real and dangerous that was at the core of The Cage and the MGM movie Forbidden Planet that inspired Roddenberry.
In both the Berman era and in TOS, virtual reality shows were a key way to explore character development, relationships and team development within the ensemble of characters.
DS9 ‘Only a Paper Moon’ is a deep dive into withdrawal from reality due to trauma. I would say it may not be as successful now because it’s too on the nose and less allegorical given the way gaming and VR are used by many with trauma and anxiety as coping mechanisms.