We had an Aprilaire whole house humidifier installed on our furnace several years ago and I think it helped. Ours has a thermometer attached outside to automatically adjust the indoor humidity so the windows don’t get condensation on them (and then mold). The downside is that it can still be fairly dry in the house - say 35%, because if it got more humid we’d get the condensation. If we didn’t have it, the humidity would get below 30% for sure. You can always forgo the thermometer if you want.
Make sure it gets installed to the hot water supply instead of the cold water supply. The first installer said it didn’t matter, but it does. Cold water doesn’t work as well. I had to get mine switched.
There is a water drain tube that leads out of the humidifier that does get moldy. I poor bleach down it every once in a while. If you get once check to see if there are any tubes that are able to resist mold growth.
Another thing to consider is if you want it to automatically turn on the furnace blower when the humidity is too low, or just to run the humidifier when the furnace turns on due to a heating call from the thermostat.