That said, olives would probably work well for it, considering their growth habit. Only as art, mind you, my wife and I'd fight over the one olive per year for the celebratory dinner salad.
The known-good techniques that produced long-term bonsai don't in any way whatsoever resemble the naive approach of "trimming" in the hedge pruning sense. This (along with the mistake of growing indoors) is why the vast majority of the public concludes bonsai is a dark art / impossible. Guessing at bonsai is like throwing rocks at a computer hoping that C code will just "happen" somehow.
If you have a sun-facing outdoor garden, know what the term "binary tree" means, and can describe a tree in terms of a data structure (nodes etc), then you have within you the ability to learn bonsai for realsies if you make contact with people who do it in real life. Olive bonsai trees are relatively common in mediterranean-climate bonsai scenes, like that of California's bonsai scene: https://bonsaitonight.com/2023/10/20/preparing-an-olive-for-...
Trees like this are not grown on kitchen counters or in living rooms. _Maybe_ in a world-beating cannabis tent, but the hassle is extreme, and (going back to the topic of this thread), fighting diseases in the indoor cultivation environment is much much harder than outside.