I did mine every year, or 20K miles.
Two reasons for that.
1) Cut one open and see how black it is inside! Fuel is filthy.
2) It keeps the bundy fittings 'exercised' so they come off easily. They are notorious for seizing on and falling apart if you wrestle them too hard, which will result in an entire new fuel line, front to back, and huge £££s.
And a 3rd reason actually, that pesky fuel filter clamp screw likes to rust to pieces if it's left to rot under there.