F1's Quietest Champion Just Changed the Sport

What the team will lose

The advantage was never just one thing. It was a tire-management profile that a different floor produces, plus a rear-suspension geometry that magnifies it. The new rules can't legislate the second part directly, but they undermine the first.

In practice, the floor-rule change is a polite way of asking the team to redesign the car around a constraint they had built around exploiting.