Let's not think that far. But yes, bitcoin can be considered a long-term investment.
Who knows when you might need it, let alone passing down to the grandchildren.
It pays to think what's going to happen in the future because you can get an advantage with that. Being with other things, it's best to save then invest in some other stuff as well.
Sure spreading your money in different investements is clever. You should never just invest in one asset like Bitcoin. But the question of thread is to invest for your children.