I run mine through the basement and fish it to wall boxes based on
https://www.homedepot.com/p/Carlon-2-Gang-Low-Voltage-Mounting-Bracket-SC200RR/202077405 and
https://tripplite.eaton.com/products/patch-panels-keystone-jacks-keystone-jacks~9-43?utm_term=keystone jack. I use BNC keystones, and I put my wired RJ45 in the same box. You can put in HDMI, fiber, and 1/8" TRS to shielded twisted pair. It would also be possible to put in shielded twisted pair Ethernet and get 4 balanced lines. If you are cutting into plaster and lath, one of the high speed vibrating saws does it cleanly.
Surface mount on the baseboard -
http://www.wiremoldproducts.com/
If you are handy, you can use a knife to break the paint line then use putty knives to carefully pry off the toe mold, then the baseboard. You can route a groove for the speaker wires and install a box on either end to transition to banana plugs or any low profile connector. At the same time, for energy efficiency on an older home you can caulk along the floor to wall gaps for air leaks found in older homes.
It is not sonically correct, but you could also put monoamps by each speaker and wireless to those. (or balanced wire)
The other approach is to find some attractive fabric and sew it into a tube, then fish the wire through it. It will attract dust, but it could be a collaborative project. One person chooses the wires and the other the fabric!