It is rife. A good proportion of my students have it with a few of them having a bad case. The worst ones I know of currently have a history of going to loads of gigs. What I find fascinating is that they still go to loud concerts. One of them recently told me that he couldn't hear properly for 5 days following a gig about a year ago, and then in the next breath said he's got another of his favourite bands booked for next month! It blows my mind. I asked him about his tinnitus and he said it's pretty deafening, and what he described sounded like a severe case. I'd say he's gotta be in his 60s. Another of the bad cases I've spoken to is a bin lorry driver.
I first noticed my tinnitus when I was around 18 or so, so that would have been around the year 2000 or so. In my case, I habituated in a matter of weeks, but I still remember reading guitar magazines and hearing the ringing and wondering if this will ever go away. Then I remember thinking, when Chris Martin spoke about his tinnitus in the media years later, yea, I've still got that. I've talked about this on here before.
Then, when I was about 32, in 2015, mine suddenly became severe and it destroyed my life. It made me quit my band, and I became really down and depressed. However, over the course of time, I found myself largely ignoring it again. This is no guarantee of how everyone else should react to their tinnitus, but it seems to be by far the most common outcome for the vast majority of people.