yes, i think it's going to be really slow, not recomended for old people to invest, i mean i don't think bitcoin will ever lose it value and to be honest i think that in the near future we will get rid of real money, we're all going to switch to bitcoin and it might be worldwide, who knows.
Why old people are not recommended to invest here? I don't see any relations between age and investing in Bitcoin. On top of that older people tend to have more spare money to invest so I do think it's a good idea for them to invest here.
What value are you talking about? Price? Because history has taught us many times that Bitcoin can rise and go down multiple times.