Mobile first design has been trending for some time now. Mobile phones are being used widely to unearth information due to its ease of use and convenience. Information is just one tap away when using mobile phones. When a user is accessing your website through his phone and doesn't be able to view information due to a broken or unattractive webpage then he is just one millisecond away to move to your competitor's page. A Stat says that 61% of users do not return to a mobile site they had trouble accessing and 40% visit a competitor's site in such cases.
Hence making a mobile friendly website is a necessity in today's time.