Telephone Jack : Experienced Users Opinion needed

I am asking for opinions from experienced campers on just how many actually USE the telephone jack in their campers. I don't have enough experience to know how many campgrounds have telephone hookups. I figured with just about everyone having cellphones, that telephone landlines (as far as camping) would just about be obsolete. Then I thought that some places may actually have wired internet too.

The reason I ask, is I did a mod to my camper where the telephone plate is, to install rca jacks from my radio. I put the telephone jack back into this modification, but see where it would have been so much easier (and cheaper) not to. I was going to post this modification, but will see what the general consensus is here on the necessity of the telephone jack is, before I decide which version of the modification to post. (along with where to buy what parts).

Thanks for any/all input.

Bobby