Is Avalanche better than Cardano?

I've been hearing a lot about Avalanche and Cardano in the crypto space, and I'm trying to decide which one is a better investment. Could you help me understand the differences between the two? Avalanche seems to have a fast transaction speed, but Cardano boasts of its scalability and security. How do these factors compare? Also, what about their ecosystems and adoption rates? Is there any significant advantage one has over the other? I'm really torn between the two and would appreciate your insights.