The antenna has an amplifier and the coax comes direct from said amplifier on the 3rd floor.
What’s pictured above is the catv setup on the bottom floor of the elevated beach house just higher than any recorded flood height locally.
Mine as pictured has a dedicated power input port (most don’t) and the only reason it uses a coax cable for power is for convenience to installers who can use the old power supply of versions that don’t have a dedicated port.
Even so, I see cable installers replacing units that don’t have the dedicated power port with ones that do but leaving the T in line.