Good question, so I Googled some answers:
How common are RAM bit flips?
Research has shown that a computer with 4GB of memory has a 96% chance of having a random “bit flip” every three days. That's a crazy high chance of data corruption occurring on your computer.18 Mar 2021
https://www.macobserver.com/columns-opinions/devils-advocate...
How often do ECC errors occur?
These can all not be corrected, but are extremely rare. A 1 Gigabit ECC DRAM contains 16 Million blocks of 64 bit datawords. Per each of these 64 bit words, one error is correctable. In other words: Statistically one out of 16 million hits might be a double-bit error.
https://www.intelligentmemory.com/support/faq/ecc-dram/how-o...