[1] https://papers.ssrn.com/sol3/papers.cfm?abstract_id=1354849
[2] https://en.wikipedia.org/wiki/Wright_brothers_patent_war
One can imagine alternative ways to monetize that R&D. Unfortunately, the main alternative historically was proprietary products and vertical integration. But one can imagine there is something better.
People will certainly use patent protection where it is available to them, but that doesn't mean they wouldn't have invested in those technologies solely on the basis of first mover advantage [0], and the lack of any observed effect of strengthening the patent system and increasing the scope of what is patentable on R&D spending tends to back that up.
[0] ARM would need a different business model, but it's unclear to me that other business models (i.e., Intel's) wouldn't have been just as successful, and wouldn't come with the social deadweight loss of patent trolls highlighted in the article.
Why? there's actually legislation specifically tailored to these kinds of problem, and it seems to work well:
https://en.wikipedia.org/wiki/Semiconductor_Chip_Protection_... (And it's equivalents in other parts of the world)
"We show that despite the existence of basic aircraft patents, aircraft manufacturers faced no patent barriers in the market dominated by government demand. We show that the notion of the aircraft patent hold-up is a myth created by government officials and used to persuade the Congress to authorize eminent domain condemnation of basic aircraft patent" https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2355673