Well 2008 is actually a better analogy as that was a bigger crash than dot com, however equities don't have a maturity date like bonds do so you can wait for equities to come back, you can't do that with that 2031 bond it's return and interest rate is baked in , you are never getting 150 euros for that 100 euros bond invested in 2021. In fact every bond since then even is not compensating for inflation, the interest rates are too low on them all but not as extreme as that 2031 maturity.You could just as easily say that, with the benefit of hindsight, equities turned out to be a poor investment at the end of 1999.
I am just drawing attention to this as so many people have loads of bonds in their pension portfolios and they need to be made wise to why their so called "low risk" funds are losing money in this inflationary period.