This meme that containers are inherently insecure just because Docker doesn't attempt to be a security product needs to die. Docker hasn't been the only player in the container runtime space for a long time.
Thus, when people bring up "Docker is insecure" I try not to get down in the weeds arguing about the specifics, and instead point out alternative projects that are designed with security in mind. I find it's a much stronger counterargument.
Secure runtimes are a superior solution to virtualisation and separate kernels. There are only two secure runtimes in common use - for javascriot and webassembly.
The point about hardware support is very unfair - if you invest the same level of effort and hardware support into webassembly, you can also i prove its performance. Thats like compaining that electric cars suck because there are no chargers - its just infra.
Docker does not provide and security or isolation.
To have security and isolation with Docker you must use something external like SELinux or AppArmor.
Hope that helps.
Regards.
How is that not isolation?