Yes. It specifies a particular level of difficulty (not too easy and not too hard), thus managing the reader's expectations and directing their focus.

The phrase will not be used for completely trivial deductions that can be done in half a second. If the previous sentence concluded that $2x=2$, nobody would write "it is therefore easy to see that $x=1$". It's easy to see that it's easy to see, so there's no value in pointing out that it's easy to see.

Likewise, if the deduction is difficult and requires hours to figure out, nobody would write "it's easy to see", because it's not, and saying it is will confuse the reader.

It's the middle ground where the deduction can take a few seconds or maybe a few minutes, where the phrase is useful. A priori, the reader does not know the difficulty of the deduction - is this a half-second thing and I'm too dense to figure it out? Is this a difficult deduction and the author is amiss for neglecting a proof, or maybe he's just making stuff up?

The statement "It's easy to see" signals that we're in the middle ground - No, you're not stupid for failing to recognize this immediately (if it were that easy, I wouldn't say anything). But yes, I'm confident that if you spend a minute you'll figure it out, so there's no need to encumber the paper with all the details.

So much power in such a simple phrase.

Yes. It specifies a particular level of difficulty (not too easy and not too hard), thus managing the reader's expectations and directing their focus.

The phrase will not be used for completely trivial deductions that can be done in half a second. If the previous sentence concluded that 2x=2, nobody would write "it is therefore easy to see that x=1". It's easy to see that it's easy to see, so there's no value in pointing out that it's easy to see.

Likewise, if the deduction is difficult and requires hours to figure out, nobody would write "it's easy to see", because it's not, and saying it is will confuse the reader.

It's the middle ground where the deduction can take a few seconds or maybe a few minutes, where the phrase is useful. A priori, the reader does not know the difficulty of the deduction - is this a half-second thing and I'm too dense to figure it out? Is this a difficult deduction and the author is remiss for neglecting a proof, or maybe he's just making stuff up?

The statement "It's easy to see" signals that we're in the middle ground - No, you're not stupid for failing to recognize this immediately (if it were that easy, I wouldn't say anything). But yes, I'm confident that if you spend a minute you'll figure it out, so there's no need to encumber the paper with all the details.

So much power in such a simple phrase.