Yes, you can take the baseboard off, cut a groove in it on a table saw, and install low voltage cabling. This would be suitable for a single Ethernet or coax. Similarly you can groove the drywall behind, but it's messier. You'll want prime paint after grooving to keep everything from falling apart.
Note that the baseboard area can be a source of air leakage into walls, and you can take the time when the baseboards are off to caulk the remaining junction.
As pictured you have hardwood floors, you must maintain a gap at the edges of hardwood to allow for thermal expansion.
High voltage power wires need to be armored, and this technique is only suitable for hiding conduit. But in some cases you can relocate a transformer (for certain types of lighting) and bury the low voltage runs.