Being in bands that have released multiple recordings, I can tell you that after around 30 or so songs, it becomes extremely difficult to write something new and compelling that you all enjoy playing. It's like you have to start to reinvent yourself, or come up with some other trick to finding new patterns of playing within the group. After that many songs, you've settled into a point where you intuitively know what the others will do, even in an improvisation. Part of the charm of many bands' "first album" is capturing that discovery phase. Nothing is predictable. Props to bands that last more than 5 years. It's very difficult to produce songs, let alone get along, lol.