nVidia is a positive outcome vs Intel. So is Apple (after all, they sell a couple hundred million units per year of compute devices with their own customized processors, which directly threatens Intel's prosperity, of course thanks again to ARM).
Or see: McDonalds vs the hundred new burger companies (Five Guys, Shake Shack et al) that have cropped up in the last 10-15 years.
Or: Anheuser Busch AmBev vs the thousands of independent brewers that have cropped up and taken an increasingly large slice of a formerly stagnant market (thanks to government regulations) with finite physical shelf space. Talk about a perfect example of how wrong the op premise is.
Tell GM & Ford not to worry about Tesla and the electric car revolution, because they can just kill off Tesla at any time (and yes, some things like that did occur, such as Tucker - thanks to government abuse in the market).
To simplify everything all patents should last 5 years max.
So nobody should ever be able to sue Amazon for infringement? Do you think other companies accountants would have trouble making profit vanish to avoid lawsuits?
But more realistically, we can list some successful outliers in a sea of tens of thousands of failed newcomers. It's very difficult indeed, but not impossible.
How many chip companies have seriously threatened Intel in 35 years? Not enough that it makes sense to invest in any of them but Intel. Picking ARM would have been pretty darn lucky.