My office's open floors have a thorough setup of noise dampening elements. The floor is some fancy carpet, the ceiling lined with some kind of foam elements, each desk has a backing made of that stuff too, and it works fairly well to keep the noise level manageable even when five people around me are in calls (which, given they're second level support, happens fairly often). Our headset have ANC and some fancy built in voice isolation system, so it's not even a bother for people on the other end.

Sure, it's not cheap, but it's neither as isolating as cubicles nor some dystopian bullshit like this. There are solutions if you're willing to spend on them (and after making a show of leading by example, our boss somehow got very willing to spend that money...)