Panasonic's TZ300/ZS300 compact camera introduces a one-inch sensor and 15x optical zoom, but omits the electronic viewfinder, raising concerns about usability for serious photographers transitioning from smartphones.
Over almost a century, Voigtländer, Zeiss, Ricoh, Olympus made attachable viewfinders. This review (The M Files, ep. 17) shows which are recommendable for your Leica or other rangefinder camera.
On the face of things, the little Voigtländer optical viewfinder is the perfect companion for the old Leica X1. That's what I thought. And then I tried the 36mm Leica version....