AFAIK, I can do with my garden whatever I want to do, as long as a I don't turn it into forrest. But that's here in Austria. What you describe sounds terrible. Fines for not mowing? In which country do you live?
In the United States most (all?) cities have local ordinances regulating lawn height. For example, in Portland, Oregon “lawn areas” can be no more than 10 inches high[1]. Mind you, this is just for the city and only applies to lawns, not gardens, or forested areas on large acreages. I imagine it stemmed from helping reduce fires near dwellings, but that is a total guess. Rural areas will have different regulations though.
>Rural areas will have different regulations though.
Sometimes those can be even worse. I lived in a town of 300 growing up, and we often had to deal with the mayor's wife and occasionally the mayor himself coming to our door to tell us we were in violation of some lawn ordinance or another. This is particularly obnoxious considering that the only way to even look up town ordinances is to go to the other side of the county to view the documents at the county office.
People are free to not move into a HoA area or gated community though. I'm looking to buy a house soon, and any HoA with any real authority causes me to reject the house based just on that. There's nothing wrong with the idea of "lets all agree to these rules that define a neighborhood we all would like to live in" in theory, but in practice the HoA contract is often a cudgel used to bludgeon people who aren't well liked into submission.
Yes, but government doesn't go away. You get HoAs that spring up outside of Denver, Austin and all the other places people from SV go when they're sick of SV. They get there and realize that while they don't miss lawn height rules they don't like their neighbor's copious power tool usage well into the evening or loud parties they create a HoA thinking that they won't recreate the situation where they come from. After all, they only want the rules to reign in or drive off a few people who's behavior they don't like. Over time the list of rules and regulations grows and personal freedom to do what you want on your own property slides down the greased slope into the abyss. It starts at reasonable noise restrictions (nothing >85 db as measured on your property line after 10pm on weeknights) and grows to include disallowing motor homes and trailers to be visible from the street, acceptable mailboxes and so on. The influx of poeple who don't want to put up with community (local government or HoA) micromanagement of what they do on their own property tapers off and is redirected at some further out suburb of whatever unnamed "up and coming" city we're talking about or to the suburbs of some other city all together. The cycle repeats itself. The road to hell is paved with good intentions.
This isn't SV specific DC, NYC or pretty much any other large city has a slow drip exodus of upper middle class people from it's suburbs to the less stifling suburbs of some other city with similar results.
This is not specific to HoAs. Most non-rural ordinances have some definition of what is legal to have for a lawn, and those generally forbid natural growth.
The issue is homes/lots in dry areas with 1-meter-high dead weeds. After the California fires, and how quickly they spread, I can understand the concern.
That said, since the drought, there are thousands of dead lawns, and I've never seen these laws enforced.
They are regularly enforced with notices to clear weeds by a date certain or they will be cleared with costs charged to the property owner, at least in some CA jurisdictions.
[1] https://www.portlandoregon.gov/citycode/article/514518