The suspension will halt resource consumption and cut down on battery usage. It means that those who have hundreds of tabs open, because they never know when they will need them, will no longer have their PC go sleepy bye-bye under the pressure.
Google claims that developers have abused timers, which often continue to work and consume resources even when the user switches to another tab.
Sadly, it will not stop background tabs playing loud audio at you until you go through all of them to find which tab it is and shut the bastard down. Maintaining real-time connections like WebSockets or WebRTC won’t be affected by the one percent CPU usage limit.
New Chrome throttles tabs
Saving processing power
Starting with Chrome 57, Google has started limiting the amount of resources background tabs can use.