I’m listing these from easiest to use to more “techie.”
Note that the easier the software the more expensive it is. Hopefully that will change but for now seems to be the trend.
Most of these AI models are open source and freely available. If you’re paying for a service from a company, it’s likely they built that service using an API of one of the free models I list here.
The only difference is how “user friendly” the UX is. Many people are still intimidated by Discord so Midjourney won’t be available to them til it’s reimagined for the masses.