Optimizing your website so that it is mobile and desktop friendly is critically important to every campaign. People are 5 times as likely to leave a website if it is not optimized.
In fact, these days Google adds a ton of weight to user experience when ranking websites. If your website is optimized so that search engines can read it to identify relevant keywords, the content is useful, and your user experience is optimized, your website will very likely do well in search engines.
I highly recommend using these tools to identify areas for optimization and to utilize your developers to update accordingly: