“No one has ever become poor by giving.” ― Anne Frank, diary of Anne Frank
Individual success does come at the expense of others, life is not a competition where one person winnings results in others losing.
Life is a long game many people play with a short term mindset. You can get to where you want to go by helping others archive their goals.
Short term thinking see people as a competitors, encouraging individuals to be selfish, horde information, keep resources, not offer assistance. In the short term you could get ahead but goodwill will run out as people stop trusting you.
For people to want to help you, you need to help them. Help others achieve their goals and you build up a network of supporters who can help you if the opportunity arises.
Helping others is a happier path, adding friends and enjoying their success and You lose little by helping and the potential upside is huge