Yeah, something like that at the time would've been mostly a b2b market, and 25 years ago it was smaller and very hard to find. Today such a publication would have a relatively easy go of it, and if you pulled on parallel markets some - garden plants, international live plant trade, etc. - you could tap a pretty reasonable market.
On AI writing, it's like cheap Chinese made plastic crap. The only market is what retailers shove down our throats as the economy flounders. The consumer wants better.
On the internet it's easier to see what people are actually looking for, and no, social media doesn't count. I'm talking about the REAL internet, the 2nd page of the Google search results. Compare BNut to r/bonsai and you'll see what I mean.

So much awful information being exchanged that success rates are lower, and quality seekers quickly seek elsewhere.
AI by it's design hits that lowest common denominator. That's the 50th percentile +/- 10. So in a bid to get the lower 60% of the potential market you ignore the top 40%. That 60%, in the case of bonsai, is largely one-offs and mallsai; previously saturated markets with very limited growth potential.
We see similar things in other industries, and we're seeing the fallout. To target 60% to maximum effect they attempt to dominate 80% of retail avenues and communications with poor quality products. Remember when the only jeans you could find were skinny jeans? It's because they took 20% less material to make but sold for the same price. So everyone tried to push the cheaply produced product on us as the "fashion."
The world is hitting a point now where the logistics costs of moving crappy products to market is going to eat through any potential profits. The entirety of the retail business sector is on the verge of bottom lining itself into the ground, all while the consumer screams for better options.
Bonsai and all related markets are separated from the game, though. Your business model can't compete with the free weed tree dug out of the yard, and the person typing it out with the dirt still under their nails. AI can't tell you how to cook a good meal because computers don't eat, nor can it properly design a garden, and it'll never write a decent plot twist. It'll take over technical writing, but not teaching children.
The bottom will drop out as soon as they realize that people will people regardless of the CEO's opinions.