[sambf]

What is the difference between your project and regular (european) plinths, which already have a built-in channel for passing cables?

[jmathai]

I've seen some trim with channels for wire. They're not very common in the US - I've never found them at The Home Depot.

For my projects, I would have to replace the trim for the entire room and possibly adjacent rooms because the baseboard is the same throughout the house.

But if you're okay with or planning to replace all of your trim and could get it off-the-shelf then certainly that's a viable option.