Happy and long-lasting relationships require love. However, they cannot be built upon love alone. They requires a few other ingredients. You need:
You need to enjoy spending time with each other. You need to be good friends with each other... that doesn't mean you need to be peers per se, but you need to enjoy each other's company. In that way, your life together becomes one long conversation
Shared goals. Life is long, and it gets really boring and difficult if you and your partner do not want the same things out of it. Whether it's:
Where you both want to live
How much time you want to spend with family
How you like to spend your free time
What you want to do for and with money
How much money is enough
Whether you want kids
How do you want to raise kids
Respect. Your partner needs to know you respect who they are, what’s important to them and you accept them as they are. You never look down upon them. No one in the world is perfect. You need to decide what flaws you're okay with, or rather, who you're okay ignoring all flaws of.
Self-awareness. You may be a high achiever, a star even, but you still have flaws and there are things about you that will tick off your partner. You also have blind spots. You need to have some humility and self-awareness to know what your strengths and weaknesses are and where your partner also excels.
Forgiveness. You will both fuck up. Many times even. But just as you would forgive your best friend after they mess up, you will need to make peace with and move forward with your partner. This is almost contrarian advice compared to modern-day relationship advice. It's certainly the opposite of what you would read on social media, which gives you an endless number of excuses to leave your partner. But I think this is quite important to have a lasting and happy relationship.
Attraction. Ya know