If you just hold on to it your 1923-dollars have become 2023-dollars, but there's still exactly $8 million of them. You've lost nearly 95% of the value.
> your 1923 dollars were likely silver dollars
It's unlikely that you had 200 metric tons of silver coins stashed away.
I think the grandparent was imagining they were silver certificate dollars[1], not actual silver dollar coins. That said, silver certificate dollars needed to be converted at some point in the past, in 2023 they can't be converted and only have collector value, and $8 million worth would dilute their collector value substantially.
[1]:https://www.investopedia.com/articles/markets-economy/090116...
In any case eight millions are several metric tons.
Also banks weren't really safe that entire time!