Along the years, I have accumulated routers from internet subscription. What I do is just connect a lan cable from main router, then plug into the wan port in another router near my room. So I will connect to my room router wifi instead. I don't even need to spend a dime, except buying lan cable 20M cat8. I can't figure out why people want to waste money on mesh.

For your case, If u going my way, I believe u can route the lan cable behind your tv cabinet from the floor, then up to your balcony curtain hiding the wires behind the rail, then come back down on the floor edge and go to master room.
Or u can go further over the door edge to your bedroom 2.

If u have false ceiling that has opening, easier to hide the cable

its obvious that is your problem and is just my suggestion which i am using btw. Works wonder, cheap and good. Cat 8 cables are cheap now. I don't see any wrong going for Cat 5 or 6 but i just like Cat 8. Again your problem doesnt mean is other peoples problem. Some might like my suggestion.
why do i care about router degration. Every 2,3 years ISP changes for you. FIFO. Best thing is it works 100% without issue. U dig?

pretty hard to draw for you. Which part you are not clear?