Businesses don't usually just completely overrun entire neighborhoods, and "opening" doesn't mean "do whatever the fuck you want". You can still specify that you don't want night clubs or auto shops in a specific place.
Mixed zoning is the norm in Europe, and it sure as fuck doesn't ruin any neighborhoods, quite the opposite in fact.
Canada too. I lived on top of a tattoo and vape store across the street from a cafe and grocery store. There were rules to keep the face of the buildings looking kept up.
I was struggling to understand this thread as a European running my business from my home, in my case I'm more of a "go visit" than "receive visits" but I also know of others in the neighborhood that do hairdressing, electronics repairs, etc.
I also have multiple supermarkets in walking distance...
It's funny, because mixed use zoning is some of the most desirable places to live in terms of market value. People don't want to drive for. Every. Single. Thing.
The argument against mixed use is often that they don't want to be forced to live in a mixed use area, but the same people are fine with forcing everyone to live how they want. Most likely they only want single family homes because they have never experienced good mixed use and can't imagine how great it is.
Home based businesses are normal in Canada where I live, people have hair, massage, other aesthetic studios, small scale businesses, professional services like counselling, etc. Heck, you can even rezone some corner properties to a neighbourhood commercial zone that only permits a handful of uses like corner stores or coffee shops.
The less homogenous a neighbourhood is the better it is for everyone. Unless you like being a slave to your car and driving 15 minutes to the store when you forgot milk.