Seriously, though. Harems are pure male fantasy. They don't want to fight for a woman to drool over them, then just want them on their knees cock-gobbling as soon as possible. This is why projects like WVM appeal to a certain subset of people, and I'm not going to take shots at specific types of people, but they know who they are.
It was a female in RL that brought up to me that she was interested in being part of a harem.
She had thought it out fairly well. She started with security for the women involved, financially and physically.
If the women all have jobs or work together in the house hold it creates a more stable situation. They can switch off on house hold chores and have a reduced load. If they each have at least a part time job it adds greater financial stability. Also with more women at home the male is less likely to stray. Thus less potential for outside illness to be brought in.
You also have built in friends and support when child rearing.
Women aren't always in the mood and having someone else around they trust to take care of the male ...
They have each other to talk to watch movies with cry on each other shoulders. They support each other...
Yep it also isn't always a bed of roses. Families also argue. But that happens in any normal family as well.
While the argument that its escapism is fair, a good story - especially romantic - aren't good without some level of conflict. I prefer realism, and realism says that attractive girls are going to be hit on (no, being avoided because you're attractive is absolutely not a thing. It happens, but it's not a thing.). It's really that simple, and for that matter, it's a game/story/VN. Just make the right choices and you don't have to worry about it.
I agree attractive women attract other men.
Consider the simple fact a male who is attractive enough that his personality won over multiple women into sharing him.
Also the benefits that relationship has for those women. They aren't just giving up on a single guy but all the other women and benefits of the relationship. Most those women are going to say no to any other male.
That's true for relationships the women are voluntarily in and are treated well.
Then you have involuntary or mistreated harems. Those an outside male might look fairly attractive or a means of escape. There are a lot of factors that determine how much the women may or may not want to leave, abuse, children...
That said even in involuntary harems women can find their treatment being better than their past life and choose it. I'm not even talking about Stockholm syndrome. Messed up but sometimes people's lives are so bad where they where that being kidnapped or involuntarily taken away from it leads to a better existence one their thankful for. Even that can be to different levels. Imagine as a teen you have a father that beats you has put you in the hospital multiple times. Your dad's a cop the other cops help cover it up. Someone sees what is going on and realizes what's going on. They take you one day. Then set you at a cabin tell you you can come and go as you please if you stay they will help you go to school feed you whatever till you are an adult what you do then is still your choice. (It's happened in RL the girl in the case chose to marry the abductor at some point). Not saying what the guy did was right. People just have different circumstances that leads to different choices in what they think is good.
Conflict:
There are far more interesting forms of conflict than having to deal with so guy most the women are going to tell fuck off anyway.
If your harem game is just about being a harem alone yea you are pretty much going to bore the piss out of reader/players.
A story about:
A you and your pirate ship that is crewed by your harem can have lots of adventures.(maybe your ship flies), could be in space...
Same if you take over or run a kingdom and you use your harem to help with that.
Your harem is your adventure party. Lots of stuff you can do there should be no end in conflict.
Your harem makes up the mercenary party you formed. So maybe you aren't taking on dragons and dungeons like the adventure but instead you sell your blades for war.
Some stories other guys might be fairly appropriate:
Imagine you and your harem run shop or restaurant or bed and breakfast or you are a traveling merchant.
All of these they would have a large amount of interactions with customers. Often male customers hit on staff. However, there could be the occasional customer who is persistent and an annoyance to the women. You know the type the one's who can't take no as an answer. That however really wouldn't be so much as competition but more you dealing with scum. Of course the girls may also deal with him and stuff could escalate in various ways.
But that shouldn't even then make it to the main story line. There are far more interesting things to deal with even just running a store. Securing supplies, traveling and learning and finding stuff, mob attempts protection racket, robbery, out maneuvering other business ... maybe research into the local government to see what you can use to get things your way.. Back room deals. Getting money back from someone that rips you off.
The point is if the best conflict you can come up with is another male trying to get a girl from a harem you don't really belong writing you'll bore people to death.