You have stated good types of investment plans for retirement but i do not find it convincing. Retirement plan means an installmental payment you make until you are out of work; which means bitcoins, bonds, or real estate is not a viable option except you earn so big. Why not just focus on saving monthly with banks? Do that for few months; then learn trading; perfect it, and do daily trading of lower percentages up until you retire.
Well, I think if someone that is already acquainted with crypto and is good at knowing when to invest and when not to invest, as well as the coin to hold for long term. I think if such an individual should decide to use that as a retirement plan, it is not too bad. In fat, he can leave t behind for generations to come. Imagine some who bought BTC about 9 years ago, he would have by now been able to make so much profit.