Hajin, you're my hero... And yeah, I don't use easy characters for easy wins, I just prefer more simplistic movesets, I'm not a fan of overly complex movesets. Easy to use also doesn't technically mean an easy win, Naotora is verryyy easy to use, but if you're not playing her correctly o if you're using her the way they want you to believe she's meant to play, it's gonna be tough to win which is why players drop her. Mai will likely be the same way, but like everyone is saying she's more popular so she'll definitely be an interesting case.
When a character is deemed easy to use, it means that they're beginner-friendly. Like if you're totally new to the competitive scene or new to fighting games in general. Those type of characters are very straightforward & to the point, often teaching you the fighting game fundamentals to its core. However, if you were to go any further with that said character, then you would have to do a lot of digging & make sure that your meta/mind games are there. And fundamentally sound. Yeah, it doesn't mean that you're going to win easy because that's the catch. Those characters are straightfoward & don't really excel at anything. This is their weakness: It makes them very predictable & not as scary to fight against. There are some characters who are easy to use, but are also extremely good, too.
Characters that are deemed "intermediate" are characters who are realistically for people who have more experience with the game, yet also a character that has strengths but also weaknesses that you have to make up for. They have attributes that could also get you into the game yet they have a "higher" learning curve since they are more on the technical side of things like executing juggling routes clean, or tech setups etc.. They tend to have more depth to them. So they are recommended, but they also may present an issue for beginners getting into the game.
Characters who are "advanced" or "high execution barriers" are the characters who are not easy to use in general. Strengths while having weaknesses, things like that. You would have to have been playing a fighting game series or the game in general for a while. Those are the characters that will take up a lot of your time to be good with. Tons of moves, hard juggles to execute, etc. If you're new starting out, then they're not recommended in general because of all of the attributes that it takes to play them. Like you would have to make sure that's the character that you absolutely want to play & no one else if you're new. They would make you feel overwhelmed & make you feel like you're not getting any better at games as well. Overall, it could make people feel intimidated. You know how that goes lol.
Don't know how that would translate to Mai in DOA, only time will tell, but this would be good to post so people would at least know.