There's only a few types of car that will be "aware" of cyclists and I don't think ringing a bell will help their algorithms. Getting the attention of a driver, meanwhile, is difficult with a bell as often they'll be in a semi-soundproof cage with loud music on. (Also deaf drivers are a thing).
I've never really considered using a bell for motorised traffic. I did once buy a loud air-horn, but it was so loud and abrasive that I never used it as it seemed really rude.