I should mention too that when I started a thread about a month ago asking what lube to use for cables the answer I got was to not bother and just get new cables. In my case though the bike WAS left out in the rain and snow 24/7 for 4 years. As it turned out I only replaced the rear derailleur cable as that was the one giving me problems and it worked. The bike is also a 1990 model, not 2019.
No, you don't need to lube your cables. If one is sticky it probably has a broken wire and needs replacing.