Here’s a great past posting explaining the differences between a preamp and an amplifier for antennas (or cable runs or distributions)
or maybe contributing factor of an antenna mounted in your attic, being obstructed by building materials, as one example. Or not getting over other obstructions if it were on top. If it could get just that much more signal… (since the TV only gets “some”)
Everything works together, to just say the tablo is at fault for having a splitter.