The finale aired here last week, and I managed to watch it on Sunday.
Having moved from three different houses in my life, I can say that "empty apartment and leaving the keys for Trigger" scene totally resonated with me.
A great show, and a great series altogether.
One of the lines I remember best is from the episode where Chandler and Joey, living in the purple apartment, misteriously got free p0rn.
Trigger: Hey, that girl is all kinds of naked!
As for not seeing each other, well, Monica and Chandler are living outside of town, Rachel and Ross will probably move in together and pay more attention to Emma and Ben, and Phoebe lives with Mike. So no more "spending half the day at Central Perk" or "walking across the hall like it's an extension of your own house". They'd be seeing each other only at weekends, then the weekends would grow farther apart, and then they'd just be an old photograph, like "Me and the Gang at Java Joe's" (from the episode where Granma Geller passed away).
I can certainly understand why Joey, living alone across strangers, would decide to move to LA and try to get his acting career going, while helping his nephew grow up.
When Angel ends (in a month for me), it's gonna be just Smallville, 24 and Joey.