"Sorry, you need log in to access this page" - sounds a little annoying for visitors but you see it often when sticking around e-commerce sites. It turns out an effective way for merchants to control over page access restriction. Magento 2 Force Login Extension help users:
Requires customers to log in to access specific pages or all the site.
Redirect customers after logging in.
The default Magento 2 customer registration link can be enabled/disabled.