16 years of saving 20% of his salary into BTC may be a wrong and risky move because of the uncertainty. I feel he should not dive into this if the saving is really towards retirement.
Sincerely, I don't see nothing wrong with the plan to put 20% of the employee's pay into bitcoin over a 16-years period.Can it, however, afford to lose it? I don't believe that because the investment is made in anticipation of retirement and the goal is to spend the money after retirement or have plans for it.I would counsel him or her to spread out his or her 20% savings among a variety of reputable investments rather than only Bitcoin.
I will also suggest that he can do like 5% in BTC for the duration of 16 years(Take the interest as often as possible) In my own opinion,20% is too high. However, if the retirement plan stated above is not available in his workplace then he should invest 15% out of the 20% in a more secure investment because he's saving towards retirement while 5% goes into BTC.
Your idea is not bad, but if he or she wants to take profit often, I think it is also good to go in that 20%, so that the profits he or she is making from the Bitcoin investment will go to other savings.but seriously According to the history of Bitcoin, it has proven to be a good investment since its existence, but the issue is that nobody knows what will happen in future,and that is why many experts are always warning new investors to invest what they can afford to lose.