Ever since the glory days of the Nexus line, Google's own reference devices have been a favourite for third-party OS tinkerers and developers. The reasons behind this favouritism are pretty self-explanatory, seeing how Google's Nesux and now the Pixel phones run pure AOSP and get regular kernel code releases out to the wide developer public. The process of tinkering and tweaking ROMs is not an easy one and a custom recovery plays a vital part in the process. Hence, it comes as no surprise that TWRP (Team Win Recovery Project) - probably the most popular custom Android recovery out there...
Source: https://www.gsmarena.com/google_pixel_3_and_pixel_3_xl_now_have_official_twrp_support-news-34050.php
