Protecting free and competitive markets is a legitimate role of the government. Banks that are “too big to fail” are too big.
Back in the old days, this country had an active anti-trust division. Its role was to prevent gargantuan companies from dominating markets and squashing competition. A monopolized market is not a free market.
AT&T was broken up into eight separate companies. It worked. The next 30 years saw amazing advances in telecommunications and a blossoming of competition.