"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?
As Dan Kennedy says, "Explorers tend to return full of arrows."
In other words, good chance of failure trying anything new.
Do something old, with a new spin.
Tip: Read through Kennedy's books (I could 60+ on my bookshelf) about how to do... business spins... slapping a new face on an old industry/niche/product.