my opinion is to quit after 5 years

then focus on the Orchestra instruments, if there is one

Our teacher said, piano study is not a lost investment, if you have another instrument, if there comes a strong competitor, if he didn't have any piano training before, you will be hampering him down on the way.

5 yrs might be long enough trainig if you don't want to commit at least 1-2 hours for your piano everyday

We had it for 7 yrs, I already decided to quit, but feeling tough....