Syncing Music from Mac to iPhone

For the last few years since Apple changed their iTunes / Apple Music set up I have had to constantly sync my whole music library of 182GB every time I want to add an album to my iPhone.

Before the changes I used to wire my iPhone to my Mac and click sync and it used to add the new tracks I have added to my iTunes every week which was quick and painless.

Now to add any new tracks to my iPhone I have to sync the entire library which takes over an hour due to the amount of music I have.

I don't subscribe to Apple Music and import or add my own mp3 tracks.

I have an iPhone 15 Pro and an Apple Air using Sonoma for the record.

It used to be so easy to just keep your whole library and just had the new tracks every week, whether that be a new album or just 1 song.

Nobody seems to have come up with an answer or understand how it changed unless I am missing something.