To be fair, Open Source has always been a threat to proprietary software. To be concrete, and I don't care what anyone else says, I will always prefer Krita to PhotoShop (because it is free, open, _and_ better, IMHO).
LLMs just make it possible to get a minimum-viable-clone very quickly (whether it is as good as a traditional open-source re-implementation, is a different matter).
The only software that I am happy to pay for is: Mathematica, and a handful of video games.
A big problem with patents is that they are designed to deprive other people of the right to practice an idea. Even if all software was automatically patented (somehow), you almost certainly would not be able to afford to defend your patents. And even if patent-defense-costs became socialized, you would still have to ensure that you are practicing fewer _external_ patents than _internal_ patents (otherwise, your royalty costs will exceed your royalty profits).
Edison industrialized the creation of patents (e.g. he would hire thousands of bright young graduates, and have them invent things, and then patent them in his own name). I once read a book that said Thomas Edison was the "greatest inventor" because he held thousands of patents. The reality is that he invented a tiny fraction of those patents, and he merely put his name on the work of other people.
My point is, if the auto-software-patent scenario becomes true, then wealthy people/organizations/oligopolies will create a patent-factory, made of either people, LLMs, or (more likely) both.
In a sense, OpenAI is already doing this for mathematical theorems (they use both LLMs _and_ a team of world-class mathematicians, much like Edison did in his day).
When I was growing up, patents were explained to us (children) as a means to protect the brilliant, solitary, but underfunded inventor -- a way to even the playing field. This has not been true for the entirety of my lifetime (36 years now), and has probably been untrue for the last century, at least.
The laws are not there to protect you and your interests, but rather they are there to protect the interests of the oligopolists (any protections you receive are _downstream_ of that).
If you want protections, you need to be sitting on top of a giant money-faucet. If you are already sitting on the money-faucet, then you probably don't strictly _need_ the protections.
Making money off of software has been a disappointing business for a while now (e.g. when I started out in the industry, the dominant business model was: turn a free Unix tool into a SaaS, and charge the innocent computer-user extortionary rents, or feed them ads, or both). The current business model is: sell plagiarism as a service.
The only reason that people talk about "moats" is because rent and food and healthcare are not free. The LLM companies are in the business of draining every moat they can find, and use the water to fill their own moat. Relying on the law to protect your moat for you is a fantasy, because every successful company finds a way to avoid or externalize the consequences of breaking the law.
Furthermore, the laws get changed whenever they become inconvenient. For example, the draft-age-limit was 35. When the Iran War started, I was relieved that I would become undraftable in less than a year. But a few months ago, they raised the limit to 42.
My rhetorical question to you (plural) is: if the establishment can change the rules, whenever they deem them inconvenient, why should we not _break_ the rules, whenever _we_ deem them inconvenient?