And it's across the board. I tell myself exactly that when I look at my toothbrush.
A toothbrush lasts about ~3 weeks before needing replacing. I'm sure someone in the industry will tell me that it's because it's made of unobtainium unicorn hair specially designed to make my teeth whiter and all that.
I also have a another plastic brush to clean my shotguns of all things (I do a lot of clay pigeon shooting) -- the construction is identical to a toothbrush, just perhaps a tad bigger. Doesn't have the fancy colored handle.
Now the brush I'm currently using I've been using for 3 years and the brush is still pretty much pristine, after being used to generously scrub bits of sharp, grim metal once or twice a week.
Hmmm... How does that work? Better unicorns? Well, think about it, everyone is changing toothbrush on a monthly basis, that is a huge revenue. Even reducing the lifetime of a toothbrush by 5% would increase the number of brushes sold by a huge amount.
All the while, it creates fantastic amount of plastic waste. Fancy packaging and 100% plastic, possibly not even all recyclable.