He doesn't like to focus on them anymore
It's sad but true
No. Its wrong.
There are simply no more arc focused completely on them.
The reason why you think that Oda doesn't care about the strawhats is because all the arcs meants to solidify the places of the strawhats in the crew are in past and most are pre timeskip.
But One Piece is not only about the strawhats :
Logue Town and reverse mountain Whiskey peak, Little Garden and Alabasta were not about the strawhats
Skypiea was not about the strawhats
The entire Summit war Saga was not about the strawhats.
In reality, there is no reason to focus specifically on a strawhat right now. Simply because they are not put in condition were they are personnaly challenged.
And yet... it still happens for some of them despite what you can say:
- PH was a good story for the development of Chopper
- Dressrosa was a good story for the development of Usopp
- Wano was a good story for the development of Zoro
And you are forgetting Whole cake. Which is literally an arc focused on all the Strawhats and Sanji.
You can also expect Usopp to get a big development in the near future.
So no. Oda is not hating on the strawhat or forgetting them. He is simply developing them with more subtilities and focusing on other character that are as important for the story in the waiting for the moment when he will developp them a lot more : Which would be at the very end of the story.