There are twelve commercial banks in the United States that on December 31, 2020, had over $250 Billion in total assets. If any of these banks failed due to mismanagement, it is highly likely that the regulators would step in to bail them out and not permit them to fail. (200 words or more please)

What are some of the advantages this gives these twelve banks over banks that are not quite as large, say between $10 Billion in total assets to $250 Billion?

What are some of the advantages this gives them over commercial banks that are considered community banks of less than $1 Billion in total assets?

For either, should these advantages be allowed? If so, what should be done to encourage formation of super-large banks? If not, what should be done to prevent it?