What you are suggesting and saying is the safest thing to do and in this way my bitcoins won't increase and only risk is bitcoin loosing value over time. I am up for little risk because Warren Buffet says - "If you don't find a way to make money while you sleep, you will work until you die". I think he is talking about passive income here and that's what i want to achieve in the long hall.
there are projects offering passive income like investing to a casino project like BETHASH. bear in mind that this isn't for the conservative investor.
what you could do is learn the signing message in wallets and lend you BTC for collateral. you earn by interest here from the forum members. you will have to choose which users to lend though, maybe those who had proven records and reputable. this is one way to grow your BTC.