A 10-15 year chart is a loooong time. I'll give you credit for patience. However, if a stock isn't paying a dividend and you are just buying and holding, how does it ever end??
I used to use Woolworth's as a great example of a stock that was either great or terrible, depending on when you bought. Currently, $TPL is that stock. I guess right now, if you held long term you'd be ok, but had you been buying and selling at the right time, it could be one of your greatest stocks ever. (I guess the same could be said for SMCI right now).
It seems to me you are just saying you buy a stock, keep it....then buy another stock and keep it....I guess if you have unlimited money come in, you can do this, but again I'd ask....is this just to pass on to someone else when you're gone? In this case, forget the ROTH. A taxable account will get a stepped up cost basis.
Just my opinion, of course.