Shared interest is key to long term relationships. Sexuality is just one possibility of many - arts, science, sports, nature, wellness, mindfulness, travel and other activities can be better together, as well.
I think, the secret of long term relationship is beeng a soulmate to your partner, meaning you prefer to do certain activities important  to your wellbeing together.
 

 Honestly I can't imagine that girl has shared interests with me, for that she should be a man. 

 Sure, partners do not need to be the same and having too much in common might be just as challenging as having nothing. 

+ Different opinions and interests also prevent boredom!

I guess, best fit is a good mix of shared an unique interests.