In my opinion it does not matter if you use 12 word or 24 word seed phrases. IF your seed words get leaked you have an issue no matter what amount of words you have used.
It's weird to see banks now just cover increasing amounts of losses because they're pushing "convenience" instead of security.
Thats just basic economics and the result of the business calculations of the bank. Even if it is weird that they intentionally weaken their security it is just that every business will require to spend money in order to then earn money. So this stolen money is simply a "weird" business expense for the banks. The will then calculate their fees exactly so they will have like 5% or something return on that business expense.