The argument for patents is simple and clear: the alternative is broader use of trade secrets. In a patent regime, a company can (indeed must) publish their process, in exchange for a temporary monopoly on exploiting it commercially. In return, everyone else can learn it, implement it for research, and improve it, at which point the patent no longer applies. Copyright was also compelling in the technological milieu i…
You forget “Benefit from state power to enforce it.” It is a subsidy from the taxpayer to private corporations, even if the patent holders participate a good share: lawyer fees at their expense, but judge salaries aren’t, and it keeps even the supreme courts busy - far from negligible. Guaranteeing patent owners that their implementation will never be used anywhere, and that the state offers this guarantee, is quite a nice gift, which could benefit everyone if people from all walks of life held patents.
If say, patents are mostly held by major corporations, then it is a subsidy from all taxpayers. Whereas trade secrets do not benefit from public enforcement. It is ok to protect everyone’s things because everyone has some, but the state still forbids holding a million dollars on the street because it would be too costly to protect. So we can say no to protecting virtual things when they are too costly for the public and when it distorts the market in favour of big corporations.