In the US, most (all?) states require a local registered agent with a non-PO box in the state. A lot of companies do good business as registered agents for out-of-state and foreign companies, where they file the paperwork and forward mail to the desired recipient.

It cannot be a letterbox. You must provide a real address that has capabilities to receive mail.

Luckily for a few euros per month you can rent quite nice addresses and the relative mail forwarding services (e.g., once a day, once a week, etc.)

In Australia, all companies must have a registered address, available on the register of companies (which isn't quite as open as I'd prefer, it isn't nearly as good as the UK's Companies House, for instance). This physical address must then have a plaque showing the registered company name roughly at the door.

In reality, just like in the Paradise Papers leaks etc, an individual accountant's office might have 4000 of these lined up next to their door.

Of course, for the vast majority of businesses, this is not much of a hurdle, and for most consumers it isn't all that helpful either, but end of the day, scammers are gonna scam, whatever the obstacles are. Even those that aren't outright scammers, will be paying accountants to have a plaque on their door to show that this is their "physical office" ...

Hopefully such efforts at least help courts assign some blame when the time comes.

When I see an imprint and see that it's a home address, I have no problems with that. It lets me know that this person is either just getting started or simply doesn't want to grow into a bigger company, probably because he/she has a real job, which are both great things, but if they scam me, I know where to contact them.

Why would I randomly show up at their house and ring their bell?

Why do you think the company needs its right to privacy but the customers that deal with that company don't need the right to know who they're dealing with ?

For your startup, aren't you setting up your DNS, webhosting, etc? aren't these small inconveniences that you're doing instead of "focusing on finding product market fit" ?

Each company, nay, each person has to do some amount of "paperwork" in order to create society that functions. Why should your startup admin be easier then my filling of personal taxes ?

At least here in Germany, you shouldn't use your home address for your business at all, because of Tax obligations, at least when you are not renting.

Because if you want to move your business later, when it grows, the tax office will regard your home as part of the business. Things will get complicated that way.

Disagree with everything you said. These are all self-created non-issues.

Dont start a company if you are so poor you cant afford a postbox.

I imagine that most people hate random Internet crazies showing up at their homes.

When one starts in a garage, one doesn’t have an office yet.