i'm here in the US, where our electric supply is fairly stable - but voltage spikes etc can damage your computer.
I use a CyberPower UPS ([strike]interruptable[/strike] uninterruptable power supply) that is pure sine wave rated - https://www.cyberpowersystems.com/product/ups/cp1350pfclcd/
it protects my computer from voltage spikes, power outages etc as well as regulates the voltage
it all depends on whether you've had a computer get fried, and not only loose the computer but the data you'd stored in it to appreciate the value of protecting your system