Site speed is incredibly important to the user experience. When a site takes too long to load, the user becomes frustrated and you risk them clicking away from your site.
According to Google, 53% of mobile users leave a sight that hasn’t loaded within 3 seconds.
3 seconds!
They stop coming back and that means they aren’t making any purchases.
Not to mention that Google has indicated that site speed is among the factors used by its algorithm to rank search results.