ようになりましょう - what is the volitional doing here?


I just came across a sentence in the structure of V+ようになりましょう, and I'd like to
understand what connotation it brings compared to the standard V+ようになる

As far as I know, ようになる is used when something becomes a certain way, in the
sense that it happened not necessarily due to someone making it so; but with
the volitional form, there's a will to have it become that way, right? To work
towards that change? And if that's the case, how does it differ from ようにする?




Do you remember the volitional form (う/よう) also has the sense of invitation or
recommendation? For example, 食べよう can mean either "(Now) I'm going to eat" or
"Let's eat". So ～ようになりましょう usually just means " **Let's** be/become ～". But
when the subject is clearly "I", it emphasizes the speaker's own
will/volition/intention.

  * 納豆を食べられるようになる。  
納豆を食べられるようになります。  
I (will) learn to eat natto.  
(More literally, "I (will) be able to eat natto." Expressed as a "fact" in the
future.)

  * 納豆を食べられるようになろう。  
納豆を食べられるようになりましょう。  
Let's learn to eat natto!  
Okay, I (decided to) learn to eat natto.  
(The meaning depends on the context, but ましょう tends to mean "Let's" because
it's has the polite ます)

  * このモンスターは成長すると空を飛ぶようになる。  
このモンスターは成長すると空を飛ぶようになります。  
This monster will start to fly when it grows up.  
(Correct: this is a description of a plain fact that happens in the future)

  * ❌このモンスターは成長すると空を飛ぶようになろう。  
❌このモンスターは成長すると空を飛ぶようになりましょう。  
(Incorrect: Since the subject is neither "I" nor "you", there is no need to
express someone's volition. Actually, the う/よう form has another uncommon
function (inference/推量), so these are not incorrect as old-fashioned sentences
said pompously by a prophet-like character. But beginners may forget this for
now.)




Do you remember the volitional form (う/よう) also has the sense of invitation or
recommendation? For example, 食べよう can mean either "(Now) I'm going to eat" or
"Let's eat". So ～ようになりましょう usually just means " **Let's** be/become ～". But
when the subject is clearly "I", it emphasizes the speaker's own
will/volition/intention.

  * 納豆を食べられるようになる。  
納豆を食べられるようになります。  
I (will) learn to eat natto.  
(More literally, "I (will) be able to eat natto." Expressed as a "fact" in the
future.)

  * 納豆を食べられるようになろう。  
納豆を食べられるようになりましょう。  
Let's learn to eat natto!  
Okay, I (decided to) learn to eat natto.  
(The meaning depends on the context, but ましょう tends to mean "Let's" because
it's has the polite ます)

  * このモンスターは成長すると空を飛ぶようになる。  
このモンスターは成長すると空を飛ぶようになります。  
This monster will start to fly when it grows up.  
(Correct: this is a description of a plain fact that happens in the future)

  * ❌このモンスターは成長すると空を飛ぶようになろう。  
❌このモンスターは成長すると空を飛ぶようになりましょう。  
(Incorrect: Since the subject is neither "I" nor "you", there is no need to
express someone's volition. Actually, the う/よう form has another uncommon
function (inference/推量), so these are not incorrect as old-fashioned sentences
said pompously by a prophet-like character. But beginners may forget this for
now.)

