Personally, I think familiars and animal companions (and even the Paladin's mount) should have been optional.
While I know they can be useful, they seldom fit my PC concepts or my DM's campaigns. And when they don't fit the DM's campaign, it doesn't matter how well you play them, they end up dead.
Example: My current PC, a spelunking Indiana Jones based character, had a Bat as his familiar. The party is going through RttToEE. He sent his bat to investigate a large, open chamber in a ruined keep. Before the critter could take a single action, the bat was snatched out of the air by the dragon that was inside. The PC is out the XP & will not get another familiar for many more months.
While I know they can be useful, they seldom fit my PC concepts or my DM's campaigns. And when they don't fit the DM's campaign, it doesn't matter how well you play them, they end up dead.
Example: My current PC, a spelunking Indiana Jones based character, had a Bat as his familiar. The party is going through RttToEE. He sent his bat to investigate a large, open chamber in a ruined keep. Before the critter could take a single action, the bat was snatched out of the air by the dragon that was inside. The PC is out the XP & will not get another familiar for many more months.