Can we access EC2 instance from MAC without bastion host

Depending on the use case, access via Serial Console may suit you as well https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/connect-to-serial-console.html

Considerations Only 1 active serial console connection is supported per instance. The serial console connection typically lasts for 1 hour unless you terminate it. However, during system maintenance, Amazon EC2 will terminate the serial console session. It takes 30 seconds to tear down a session after you've disconnected from the serial console in order to allow a new session. Supported serial console port for Linux: ttyS0 When you connect to the serial console, you might observe a slight drop in your instance’s throughput.