What are Tezos' weaknesses?

Could you elaborate on the potential weaknesses of the Tezos blockchain? Are there any scalability issues that might hinder its growth? Additionally, what are the challenges associated with its governance mechanism? Are there any security vulnerabilities that have been identified? Furthermore, how does Tezos compare to other leading blockchains in terms of transaction speed and cost? Finally, are there any specific concerns or criticisms raised by industry experts regarding Tezos?