I think that the differences in points of view here are we are comparing the average, every day driver to Louis Hamilton.
90% of us play purely for the enjoyment we get and, although we would like to improve, it's not a big deal as we play for ourselves and not to please some governing board of examiners or a paying audience. A lot of us never had specific tuition on the accordion from a teacher and likely never will, although we may have had tuition in other musical areas.
Judging by the initial inquiries on here I think there are those who overthink the whole process and, rather than just diving in and having a go.
If you are a serious student then get a tutor and do what they advise. They are the experts.
If you are like the rest of us here, try for yourself, then ask away but you will need to sort out the answer for yourself among all the different solutions you will be offered.
In my time, I have tried playing dozens of different musical instruments and the only one I didn't succeed in getting a tune out of within 10 minutes, (including violin) was the great highland bagpipe ( which is incidently my main instrument for which I had proper tuition for many years.)
Note to self "shut up"