I have a Verbatim M-DISC BD-R that I torture test. It was one of the first ones I burned. I burned it in 2018. I flex it all the time, use it as a coaster on my desk, leave it out on my patio in the sun for weeks at a time. I rinse it off with pool water and wipe it off with paper towels. It has yet to lose a single bit.

If this 20ish gigs of data hasn't had a single bit of corruption, I doubt most of the other discs in climate controlled storage in multiple locations have had much errors either.