If I'll ever find my self in a situation like this - I'll pack my things and run. I'm not going to be happy in a place like this even if government will force those people to tolerate me.
> if a majority of businesses gradually decide to be racist and refuse all services just because they can
That means anyone entrepreneurial enough will have access to an underserved niche market.
An underserved niche market of people who have significantly less money because they can't find work - and your company won't hire them because your other customers who actually have money will boycott you - isn't worth much.
This is an important point that those in disagreement with these kind of arguments often under-emphasize or ignore entirely. When a government makes it illegal to behave in a racist way, the racists don't go away, and they might even be amplified within those communities in a similar way to the Streisand effect.
If everyone in a community is racist, you can't simply make it illegal to be racist to fix the problem. They have to make that decision on their own - anything else is fundamentally authoritarianism, which doesn't have a great history of long-term success.
A food establishment forced to serve you might serve you food that's gone bad, a mechanic might not fully tighten the nuts on your brake pads, or any other variety of horrible things that people could do to harm you while leaving room for plausible deniability.
At least if they can legally deny service to you, you know that the ones serving you aren't a risk to your wellbeing. And to that end, I think it's a bit unfair to suggest that less money means there would be no businesses to serve that group of people. If every restaurant is discriminating, the singular restuarant that serves the less wealthy group would have plenty of business, simply due to the lack of competition.
The "pro-regulation" argument is valid with regard to a less commoditized market though, which is interesting. For example, I wouldn't want the only company that makes a life-saving drug to be able to legally discrimate who they sell it to.
It's a challenging problem and I certainly see both sides. My gut goes to regulations affecting large businesses but not smaller ones. It feels like there are probably some difficult edge-cases within there though.
What if the government, which issues identity documents that allow you to "run", decides they just don't like you and declines to produce them?
Assuming that refusal-of-service is a sort of relief valve is wildly optimistic.
Overt but relatively passive forms of racism effectively give pervasive comfort and encouragement to those who would engage in more active acts. Indirectly, this is also why "dog whistle" speech is so dangerous.
Per your example, in an environment where simply refusing service to you was common and widespread, you might find that someone who does agree to serve you is doing so just for the opportunity to spit in your food (at best).
Depends on how spread out the population is - black folk, maybe (but I don't have a simulation on me to work it out for sure and in what situations that theory might collapse), the subset of trans folk who're still working out how to blend in and not be seen as such in a rural area, not so much.
There's entire countries where some products are just not available commercially due to the lower income meaning nobody wants to put in the effort to work out how to provide them cost-effectively.
AFAIK there is no strict control on US state borders, citizens are allowed to move freely. In many cases running away is as easy as purchasing Greyhound bus ticket. It's great that you deeply care about prosecution of LGBT people in places like Middle East, but it's not really relevant to a discussion of anti discrimination laws in US.
> isn't worth much
You don't have to be big to be successful. This scenario means that you have very low barrier to enter this market and will have to spend close to nothing on advertising. But what's more important - this scenario is unrealistic. If you live in a country where it's possible to pass anti-discrimination laws - you don't need those laws, since majority of your country already finds discrimination unacceptable.
The majority of a country finding discrimination unacceptable isn't necessary to pass anti-discrimination laws - just that most people don't care whether someone gets discriminated against or not. If you don't care (or need the job to survive yourself), you'll do whatever your boss tells you to do, and you're hardly going to boycott a store for discriminating against someone else, which means a subset of the population has disproportionate impact.