Maybe you’re imagining no local privilege escalation vulnerabilities. Those are low severity in general, but if you can get a user to run something it’s all over.

How much do I need to go on? A foothold on a local computer allows the attacker to spread horizontally across your network.

It’s just a matter of time before you’re fighting real-time AI-driven attacks (most sites aren’t yet). Good luck even with your antivirus. Which I agree is going to be one of the footholds that is used against you.