I have several rifles including a 7mm mag, 270 mag, and 308 but i would have to say when going out the 308 is my least favorite rifle. I think my 7mm and 270 fly faster flatter and have more knock down power. Maybe im wrong but i bought the 308 reading how its so popular and do not really care for it or understand why everyone likes it so much
A quick summary:
Popularity and affordability (cartridge in service)
Short action with ready to run short action systems from bolt or autoloaders and preban magazine options.
Extreme Accuracy and as good or better as any other.
Consistency of ammunition
Amazing bullet department with choices for anything you need and also budget friendly match grade value packs.
Surplus for practice at lower cost.
etc...
If you like flat shooting try a palma type of load in the 308winchester. you might be surprised.
There are also other cartriges that shoot even flatter and reach further than the 7mm and the 270 but also come with a price tag and trade offs just like those you mention.
Shoot what you enjoy shooting and have fun but there are very good reasons for people to like the 308w too.