It's mostly a matter of personal preference. I prefer mouse and keyboard to touch controls most (but not all) of the time. I tend to be very wordy and find a physical keyboard to be a lot easier to use than a virtual one. I tend to prefer larger screens over smaller ones. I really like the personalization options that are available on desktop for a lot of things through third-party tools, apps, and extensions that are more common on desktop than on mobile. Things like that.

I have a smartphone and a tablet, both of which I use for particular things and have used for social media (mostly RIF), but if ever there was the choice of using a desktop or laptop instead, I'd go for that. Unless something is enhanced with touch controls, and I have never found that any social media that I use is, I just don't prefer mobile platforms. And for a short time, I had a laptop that had a touchscreen, and honestly liked that a lot more than using my phone for some of the things they could both do.

Just to establish my own timeline, I got my first cell phone when I was about thirteen, and I got my first smartphone when I was in my late teens if I recall correctly. So it's not like I haven't been around them long enough. I just never found a preference for them.