Yes and no. There are countless innovations that have been lost over time (I.E. Ancient Roman's had stainless steel but it was lost), some were rediscovered so

Yes and no. There are countless innovations that have been lost over time (I.E. Ancient Roman's had stainless steel but it was lost), some were rediscovered some weren't, patents hope to prevent that by giving some incentive. This hasn't always worked though, for example Philo Farnsworth basically invented the modern TV but the large companies just waited for his patent to expire before moving on thus making it so he never really got paid anything but to contrast that the expiration on patents for 3D printers is what's causing so much innovation in that space today. The main problem is when stupid ones (like the same thing as before but now with software) are granted it drags everything down, and the very concept of patent trolls is a destructive force not contributing to humanity at all. Combine that with how most patents are forced through by submitting it until it sticks and it's a pretty broken system tbh.