Why is this special way of encrypting and storing the seedphrase file inside 1password a BAD idea?

Genuine question. I am not talking about saving the seed as-is in 1password. I am trying to understand why the following method could be breached:

1. Save your seedphrase in an excel file
2. Password protect this excel file 10 times. For example, it gets zipped with password protection -> gets zipped again with password protection -> … a total of 10x
3. Write down 5 of the password sets in one piece of paper. Then the other 5 password sets in another piece of paper.
4. Put one paper in the safety deposit box from Bank A. Put the other paper in a different safety deposit box in Bank B. Have the overall instructions stored somewhere safe.

This way if 1password gets breached, hackers likely won't know that zipped file contains seedphrase and they won't be able to crack open the 10 level deep of passwords.

On another hand, if one or even both deposit boxes get compromised, they won't have the electronic file to use it on, and they probably don't know what they are for.

Please roast my idea, or suggest ways to improve.

I know the general consensus is to just write it on a piece of paper and put it inside a fireproof bag, or engrave it onto a metal plate. My suggestion above is the last resort backup in case something catastrophic happens.