It can work really well….as long as the pieces are chosen carefully. For example a retro vinyl and formica 50’s table wouldn’t go well in a dining room that opened into a Louis XIV inspired living room…with an embellished rococo French sofa and matching rococo chairs, mirror, etc. It would be too jarring. But you could possibly put two Corbusier armchairs with a French sofa and it would work. The clean lines of the Corbusier would temper the o.t.t. embellishment of the carved sofa. It’s all about lines and balance in a room.
It all depends…but once again….it is possible. Photos would help (as someone suggested).