Just musing about this, mine's pretty knackered. It's looking rough, splits and cracks. I was going to order a new one but then though 'is it actually worth it'? I mean it's flimsy plastic, how much protection can it really offer? Does anyone ride without it?

Yes, all the guards are worth fitting , except for when you are a works rider and do not pay to fix the bike.

It's also there for the benefit of your minders fingers. Competition rules may even require the safety guards be in place if you are competing in a sanctioned event.

... if you are riding in winter they become a problem with ice buildup and I remove the guard seasonally, but studded tires are crazy dangerous so only crazy people would ride or catch studded tire bikes in winter.