He's had a bit of an odd career. Obviously won a lot at City but he's played 10 PL games this season. A decent amount last season but the one before that only 16 PL games.
Also only has 20 caps at nearly 29 years old.
From my understanding, the season before last he lost his spot to Dias and Stones, who had a good pairing the entire CL run to the final they conceed only 5 goals, so far its the same this season they've conceeded only 5 goals, last season when Laporte started they conceeded 16 goals, so in comparision the 2 CL campaign without Laporte they conceeded a combined 10 goals and 1 CL campaign with him they conceeded 16, so he's been poor for them in this competition.
This season it seems he was injured till Nov I believe at the time Ake/Akanji were doing really well, followed by Stones and Dias form improving as the season went and he lost his spot. Will be gone this summer from what it seems like. Good defender for league play though. I feel he'll go to PSG or Barcelona.
I feel bad for him, as I heard he played through injuries last season in the final game to ensure City title win, which is why he was injured, but this also goes to show how ruthless Pep is, there is no sentimental value, he won't care what you did last season, its what you do now.