"We chat" is just to combination of multiple apps. There are many apps with similar concepts like messenger apps. You hardly find any uniqueness in Skype, WhatsApp, Viber and signal etc. but all are successful and have billions of users. They all trying to solve same problem with similar solutions. The only difference you find is UI design and some minor things. Similarly, Udemy, LinkedIn learning, Lynda and Edx offers almost same services. Do we need to find problem or can we solve same problem which is being resolved by competitors?
You might need to do both, and it depends on your ideal customer's buying patterns. If that buyer typically purchases your product and your competitor's product in a single transaction, and that buying pattern makes sense, you gotta to build, buy, or partner to offer your competitor's product. If you don't, you could quickly get shut out of the market altogether.
Partnerships are messy, but they're so fun. It's good to have friends in the market, and making the choice to partner can really clarify your company's purpose: the problem you want to be known for solving better than anyone.
Last thought: when you do pick a truly new problem to invest in solving, just make sure it's one you and your team care deeply about. You only got so much time to play with--do you really want to use it building a better mousetrap?