Depends on the complexity of the page. A lot of sites with heavier JS and SPAs eat a lot of memory which can cause problems for users of the many laptops out there with 4/8GB of RAM, as well as many smartphone users who have 2GB of RAM or less. In the case of the latter visiting a heavy website can be enough to prompt the OS to kill some other app to make memory available, which means in that situation one's site is in direct competition with other things the user may be needing more than the site.