Yes, if your WordPress website is built properly, it should be mobile-responsive and accessible on all devices. This means that the website should automatically adjust its layout and design to fit the screen size of the device it is being viewed on, such as a desktop computer, laptop, tablet, or smartphone.
Having a mobile-responsive website is important because more and more people are accessing the internet on mobile devices. In fact, according to Statista, mobile devices accounted for approximately 54% of global website traffic in 2021.
To ensure that your WordPress website is mobile-responsive, your agency should use a responsive theme and design, which adjusts the layout and elements of the website based on the screen size of the device being used. The agency should also test the website on multiple devices to ensure that it is functioning properly and all content is accessible.