Meaning of the word "be (strictly) for the birds" in English

What does "be (strictly) for the birds" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

be (strictly) for the birds

US /bi fɔr ðə bɜrdz/
UK /bi fɔː ðə bɜːdz/
"be (strictly) for the birds" picture

Idiom

to be worthless, silly, or not worth considering

Example:
His advice is strictly for the birds.
I think this whole plan is for the birds.