I do. These days it's all over the place - much of it on here, bookmarked, much also in other online support places, numerous notebooks and bits of paper and random files on various digital memories. I used to keep my journals 'properly' - in books, consecutively - but my partners read & used them against me, as did other people at odd times. I destroyed all the old ones. I think I'll regret this as, if I ever get around to telling the interesting bits of my life story, all my most personal records have gone (I ditched photos & memory boxes too.)
The primary purpose of my journals, though, is the benefit in the act of writing them. From this point of view alone, I don't need them stored for more than a few months. I'm about to clear out all the old paper; journals will go with it.
I think that, if yours are for your older self to read, it's a good idea to store them directly on a big corporate server somewhere far away. You could either use an online blogging tool, with careful privacy management, or upload your stuff to something like a no-visibility, password protected Dropbox folder and delete them from your device. A physical alternative would be a safe deposit with a bank or solicitor - or you could just keep them in locked boxes at home, and refuse to open them for anyone!
I'm sure it's daft to worry overmuch about this ... but, well, it's horrid when other people read 'the inside of your head' without asking, and I wish virtual filing had been available to me back then.