It is not good advice to focus all your efforts on just one investment because there are multiple sources of income and many investments that could quickly bring you to a place of financial independence. Overdiversification is not advised, but not that diversifying at all can be quite as bad as that.

Having stock investments and crypto investments is not so difficult and should not be difficult for you to manage. You mostly feel you cannot right now because you have not tried it.

Having investments in stocks and crypto can give you more confidence about the future.