Pi 4 has over twice the performance per watt (see the-diy-life.com/raspberry-pi-drag-race-pi-1-to-p…), so I think that may be the sweet spot for certain uses, but I agree that the 3 is still a perfectly capable device for so many projects.

Also the 3 is the last one to have a full HDMI port which is makes it really appealing for display related projects.