How is protecting one's patent thwarting competition?
That's what patents are for.
If inventors didn't have limited exclusive rights to their works there would less incentive to innovate.
That assumption has never been proven. The greatest inventions in the last hundred years have never been patented.
And what's a "limited" right in this age? In the 19th century, when there were fewer people and even fewer who had the education to invent complicated things, 25 years seemed apt. These days, with ten times the population and more than 95% literacy rate, two years would still be comparatively more than was originally held necessary.
We'd all be riding horse and cooking our fresh kill deer on an open flame and sending messages out via smoke puffs.
The Ford Model T was introduced in 1908. It revolutionised America's industry. With the help of patent law Ford couldn't have started selling cars until 1910 (Benz's patent was granted in 1885).
Can you imagine a world without Henry Ford's invention of massproduction?
The telephone is not a really good example for the benefits of patents either. Several people invented the telephone. But only one company ultimately held the patent for the "invention" of "the telephone".
That company became a famous monopoly (a real one, not just a company with high market share). Luckily some people could still imagine a world as it could be without that monopoly and that's why we have competing phone companies now.
Note that the telephone was invented by lots of people, and they didn't do it because patents were there to reward them. But patents made the invention into a monopoly. So both the invention of the telephone and the patent for the telephone changed the world. But while the invention changed it for the better, the patent only changed it for the worse.
I am not saying that patents are bad or always hurt innovation. But to argue that they create innovation so exclusively that they are definitely needed is foolish as is arguing that they must cover the same period of time they had to cover in 1846.