Originally Posted by TheLegacy

Well - very shortly you won't have a choice. If you don't turn on GA4 before Universal Analytics sunsets in July 2023, data will no longer be collected from users on your website, leaving you blind to what's happening on your website. You won't know where users are coming from, how long they're staying on your site, where they're dropping off and more. You can still access any previously processed data on Universal Analytics until 2024. (Originally end of 2023, but Google extended it to give businesses more time for the transition)

If you want some help doing it let me know