I believe traditionally the two main purposes of Urdu Shayari were; first, to romanticize the beauty of your loved one, and second to romanticize the separation from the loved one. Later on, Shayari is used for various purposes such as social messages, sharing revolutionary thoughts, etc. But the theme is to romanticize things. I also think that these people were the most romantic people, capable of romanticizing every emotion be it love, pain etc.
dil-e-nādāñ tujhe huā kyā hai
āḳhir is dard kī davā kyā hai
Mirza Galib expresses his one-sided love in such a lovely way and the whole Shayari is filled with Shers that reach the depth of your heart.
My love for Shayari was always there, but I felt all those words when I fell in love. And the only good thing about the breakup was that I could experience the pain they expressed through their words.
ye mujhe chain kyuuñ nahīñ paḌtā
ek hī shaḳhs thā jahān meñ kyā
Oh! What words by Jaun Eliya.
ab ke ham bichhḌe to shāyad kabhī ḳhvāboñ meñ mileñ
jis tarah sūkhe hue phuul kitāboñ meñ mileñ
Uff! Ahmed Faraz
I wish I could express myself in such a way, but I have learned a lot from Poets like Mirza Galib, Ahmed Faraz, Meer, Sahir, and many others.
pattā pattā buuTā buuTā haal hamārā jaane hai
jaane na jaane gul hī na jaane baaġh to saarā jaane hai
Here, Meer says that the whole world has come to know about my love for you, but still somehow you have no clue.
One of the most beautiful parts about Shayari is that though often there is a simple point to be delivered yet it is done in such a way that it always says the whole story.
I like Mirza Galib because he seems to be a very sensitive guy and being a sensitive guy in the 19th century was definitely not appropriate. He was not an ideal 19th-century guy. Men were supposed to be strong, insensitive, emotionally unavailable but Galib never shied away from expressing his feelings. Mirza was mocked as behaving like a woman. So, he says,
dil hī to hai na sañg-o-ḳhisht dard se bhar na aa.e kyuuñ
ro.eñge ham hazār baar koī hameñ satā.e kyuuñ
Here he clearly says that, if someone torments me I will cry be it thousand times because my heart also fills up with pain and it’s not something made of stones and bricks.