I've seen vibration travel a long way in concrete framed buildings. The absolute worst is when you have a rooftop loading dock - a 19m semi going over a movement joint was enough to shake stock off shelves in the store below it. The other common problem is HVAC plant starting up (or ramping up quickly) and shaking the structure.
The best gym I ever trained at was shut down because the landlord leased the space next to ours to a hot yoga studio and they bitched and moaned about the noise and vibrations of guys setting down 500 lb and heavier dead lifts. They even accused one of our members of pissing on their door handle.
That's a unique case; mechanical vibration. If not dealt with appropriately, via isolation usually, yes, it's a problem.
I was talking more about foot traffic causing the floors to bounce which is very common. This happens because bays or the spaces between lines of columns tend to be regular. You can very easily design a floor that has enough strength for a given span, but will often be too flexible to meet vibration recommendations for comfort. It's been a while, but I don't think there was a Code requirement for vibration, so there's that. It's a careful dance you have to perform between number of joists, spacing, joist size, and what floor system you end up using.
Steel is inherently more flexible than concrete for a given strength of element, so a lot of times you just neglect checking the bounce of the floor in a concrete system. Steel frames you have to do it all the time. I learned this the hard way early in my career.
Haha, yes, it was a damn good black iron gym! One of our members was a welding instructor at a local community college and he made a ton of equipment for us. We had platforms, racks, benches, monolifts, prowlers, strongman stuff, and tons of plates. We had some damn good lifters, too. Guys that could squat close to 1000, bench 700, etc.
Cool. My gym has moved a couple times, but still has many 'original' pieces made to spec by local welders. The beat-up power rack made from heavy C-channel steel that has a little wobble, a bent bar, and that no one squats in - is the owner's favorite squat rack.