Difference between ～てばかりいる and ～てばかりだ?


Can anyone please explain the nuances between ～てばかりいる and ～てばかりだ?

I've come across several sentences like:

> カップラーメンを食べてばかりです。

> カップラーメンを食べてばかりいます。

and

> ゲームをしてばかりだ。

> ゲームをしてばかりいる。

but don't understand what the difference is.

Someone told me ～てばかりだ is rarely used. Someone else said that one is more
formal and objective than the other. Websites have said that they're both the
same. I'm so confused.




I couldn't find a proper reference. But ultimately it seems like the
difference in meaning should be the same as the difference between だ and いる.
The difference between being and existing.

カップラーメンを食べてばかりいます。They eat ramen all the time.

カップラーメンを食べてばかりです。 They only eat instant ramen. And maybe they will do so
forever. They're _that kind of people_.

It seems to me the ばかりだ formulation is more judgemental regarding the very
nature of the target of the affirmation. Whereas the ばかりでいる is merely an
observation, though with a negative connotation too.

うちの子がゲームをしてばかりいると言われても否定できないが、だからといって将来なんてないとはとても言えないと思います。

あいつは、ゲームをしてばかりで、将来のない人ですよ！

