I still use my landline a lot. Much more so than my mobile. Mainly because it's a lot cheaper. Calling for one hour landline to landline costs about 1.5 euros here. Calling for one hour on my mobile easily costs about 10 times as much. (there are also subscriptions that are cheaper, but the subscription fee is A LOT higher too then)
Calling landline to mobile is a bit cheaper than mobile to mobile, but since a lot of my contacts only have a mobile phone these days, the cost of calling mobile phones is easily 80% of the landline bill, while it's not even 20% of the calling time.
I mainly use my mobile for texting and to be reachable, not for calling itself.