Selenium test automation framework has matured over the years and provides multiple options to do every kind of test automation - be it websites or mobile apps.

For manual tester very good tool, zero coding is required

Selenium comes with many advantages, but it is widely accepted as it is an open source and community driven. It provides compatibility between different browsers and platforms which significantly reduces the workload of testing it across various browsers and platform. It supports almost all of the programming languages that I use. Other significant feature that I like about Selenium is it's parallel test execution and integration with frameworks like JUnit and TestNG.