The government should not be toothless in human rights issues, it should be the fiercest defender of liberty.
In terms of discrimination, it wouldn't be very different if protestors spread awareness about shitty businesses. You're right that Civil Rights Act can't be passed in a libertarian society. But that just means there were not enough social systems in place to shame bigots and shut down their businesses.
A libertarian society has to have replacements for the functions of government. For example, if we want to privatize welfare programs, the charity organizations must have enough funding privately to cover all the functions government transfers do. So you can't just insert a libertarian society into the past and claim it wouldn't work. Because it wouldn't, and it won't work if we switched to it now.
But let's say we started deregulating businesses in key areas like manufacturing. You still need environmental protections (because pollution is meddling in other people's lives), but we basically forgot how to build things in this country. In the event of a war with China over Taiwan, we would get outproduced eventually as they switch their factories from exporting goods to making things for the military.
The MAGA idiots being out in the open is great, now they are bitching about being discriminated for being conservative. But that's how a libertarian society would deal with intolerant people - by not tolerating them.
So the functions of the government like security and protection of liberty is just as important to libertarians. We're just not so eager to reduce liberty to hopefully force a good outcome.