Minimum risk is possible for the long term but not risk-free or say 0 risk when it comes to bitcoin.
Everything has a risk especially when talking about bitcoin so we cannot say risk-free bitcoin even 0 risk even if it is done for the long term even though bitcoin is still very worth it to do.
In this context for the long term we actually only minimize risk because at least with the long term our risk will be smaller than for the short term but that does not mean this is 0 risk because after all when we talk about bitcoin and invest in it there will be no such thing as 0 risk. Don't because we are too sure that we forget or eliminate important things as if it were certainty even though risk is quite closely related when we are in the scope of bitcoin.
There is no risk-free investment - all have risks, but the risks are never the same. The risks of investing in bitcoin and altcoin are different - it is true that you can lose money, but the big risk of investing in altcoin is that you have no chance of recovering when the altcoin is no longer in demand by investors and the altcoin dies on its own. Bitcoin will never be in that position - it is quite reliable as a long-term investment, but you have to be able to understand the risks and minimize them.
There are many guides on how to control risk and how to minimize it - we can all learn. The risk is not only about the price changes - but also about how you secure your bitcoin and store it. One example of minimizing the risk of bitcoin investment is - do not store your bitcoin online.
For this context, we almost all agree not to talk about altcoins, especially in the discussion in this thread because in the end the focus of the discussion is more directed towards investing in bitcoin so altcoins are unlikely to be accepted in the discussion for this thread.
But back again regardless of anything for now wherever you are in the end the risk will remain regardless of whether it is different or not (of all the risks) still the name risk remains a risk as well as being in bitcoin so there is no such thing as risk free or 0 risk.
As for why we choose the long term in the investment made is because indeed in the end when we are in a long period of time to invest in bitcoin at least we can manage our risk to be smaller than the short term or even trading because the risk is much greater. So that with the long term we can reduce the risk we will face because for the long term it is possible that volatility will be lower besides that we also still expect that in the end the long term can expect better growth potential.