Yes, unless you are clueless and execute any executable that manages to hop onto your machine. AV is complex code that handles huge amounts of untrusted data,

Yes, unless you are clueless and execute any executable that manages to hop onto your machine. AV is complex code that handles huge amounts of untrusted data, so it's a major increase in attack surface. Also, it cannot work, as it's an instance of blacklist security, which never works. So, no upside, huge potential downside.