What are the disadvantages of ETH?

Could you please elaborate on the disadvantages of Ethereum (ETH)? I'm interested in understanding its limitations, particularly in terms of scalability, security vulnerabilities, and transaction fees. Additionally, how does ETH fare in comparison to other cryptocurrencies in these aspects? Is there any risk associated with investing in ETH given its disadvantages? I'm keen to gain a comprehensive understanding of its shortcomings to make informed decisions.