Why YouTube Music UI is not consistent with the rest of Google's services? (Material You)

It's not an issue as such, but the UI could be improved to make it look more modern and in line with other Google services. Material You is very beautiful, why not use it?

Credits: https://x.com/SLKVinyl/status/1878640950500868380

https://preview.redd.it/rgtts4br4lje1.png?width=1678&format=png&auto=webp&s=7f425f352a08602621a5e6ab356e63fd7721d508