I’m not sure what all other messenger apps out there do differently than Apple’s Messages.app but the syncronization between devices is always consistently the worst. Apple of all companies should be the one to nail cross device sync in their own ecosystem.
After waking up the computer, messages from hours ago stay unread until I click on each conversation to make the badge go away. Restarting Messages.app doesn’t fix that. Clicking on a conversation sometimes replays the messages with a “new message arrived” notification sound for each message. If this is hundreds of messages this results in a few seconds of notification sounds being played in quick succession and sometimes overlapping.