OP, my opinion is almost everybody has tinnitus on some level. For example the ringing we may hear throughout our lives...called fleeting tinnitus....is normal.
What I believe we have with people that come to this forum, are extreme cases. This ranges from tolerable to desperate really based upon tinnitus dB level. People that struggle that come to this forum for insight and help have more of a perfect storm between brain and/or damage to their hearing apparatus.
Most things in life from height to eye color to IQ to athleticism to artist capability...pretty much all things are a bell curve. For each characteristic statistically we somewhere fit in. With many here, our tinnitus is 3-4 standard deviations to the right of average. We are outliers and there are many reasons and likely a combination of physic reasons why our tinnitus is loud and others can't hear theirs.
I am begrudgingly entering the ranks of being a senior now. I had pretty perfect hearing and no tinnitus my entire life...other than common if not normal fleeting tinnitus I never paid attention to. But at times now, I have tinnitus from hell as do many here. Btw, my grandmother had it too. Hereditary is a big factor as well as in most physical traits...our genetic breakdown exposed as we age.