The Smartphone is not completely degoogled. Please check before posting such statements. It can not be compared to Graphene. Graphene is far ahead.
See: https://divestos.org/misc/e.txt for a list of issues
/e/ is very slow in terms of security updates and they rely on some google services.
The only point you can make: If you want it easy and you don't care about security and less google but not degoogled is okay for you, /e/ is your choice.
But please stay away from Fairphone. They have several hardware issues even in more than one generation (for example ghost inputs in 3 and 4) but they do not accept them and try to solve with software update which surprisingly did not work. And if you use /e/ you don't geht support from FP side.
Addition: