One of the major issues with blogger currently (as at the time of writing this) is that their templates are not responsive. When we talk about responsiveness, we refer to the ability of a website to respond to various device widths.
Many devices vary in width, and a website must adapt to those different screen widths for the best user experience. WordPress has an edge over Blogger because of this responsiveness. Most WordPress themes are responsive.
Why did I have to include this? Majority of the people visiting your blog are going to do so from a mobile device, and those mobile device will vary in screen width. If your blog does not respond to those variations, you are going to lose out because bad user experience may force your visitors to run away, even without reading at all.
Google has a GoMo tool that can help analyze the way your website responds to mobile devices. Google will also rank websites that have mobile versions higher when searched from a mobile device.
If you are not sure of this, contact the person who designed your blog and make sure your blog does well on mobile devices.