Should I buy arbitrum or optimism?

Should I invest in Arbitrum or Optimism? I've been hearing a lot about both these blockchain projects, but I'm not quite sure which one to choose. Arbitrum seems to have strong scalability features, while Optimism is touted for its user-friendly interface and development ecosystem. Could you help me understand the pros and cons of each? Are there any key factors I should consider before making a decision? Additionally, how do these platforms compare in terms of security, transaction speeds, and adoption rates? I'd appreciate your insights on this matter.