Bank investors have more certainty because their capital is completely safe but they give 8-10% annual profits to the investors of per year. But it is comparatively less in terms of profits.
Who says that bank investors' capital is safe, with all the inflation that has been ravaging the entire global economy where if you keep $2000 in the bank you get a low interest at the same time depreciation of the value of that amount, say in one year the value of your capital will reduce by almost 20% say you kept 2k in the bank by the end of the one-year investment cycle, the value of your initial capital might have rescued from the $2000 to $1800 or even less in some cases so you already on a loses trend with bank savings.
Altcoins investment on the other hand is a a high-risk gamble and if you want to invest in any coin for the long term, it should be Bitcoin because only Bitcoin will give you that stability of investment that is void of pump/dump mechanism, but if you invest in altcoin you should careful because you can lose some or your entire capital in the process.