Free software would not go anywhere. The only difference is, without a right to repair law for software in a post-IP world, people writing software may or may not choose to withhold source code. But the trick is anyone who ever gets that source code can (unless under an NDA or contract not to) distribute it all they want. And the receivers of software will be able to distribute it however they want. The profit motive of artificial scarcity goes away, and if you try to use your holding of the source hostage as a way to keep users dependent on you all it takes is one leak to end your monopoly.
That being said, right to repair goes hand in hand with the abolition of IP to resolve these edge cases. The problem of not providing the manual to your distributed invention goes far beyond just intellectual property, and is largely an independent issue, but good right to repair legislation is all encompassing, and is a consumer protection that naturally fits with IP-less software as well.
> ...all it takes is one leak to end your monopoly
I don't know about that. Most significant software packages require ongoing maintenance (bug fixes, security patches, compatibility with other software) and add new features over time. A one-time leak certainly would be damaging but not necessarily fatal since most businesses want to have assured support and upgrades.
The difference is that before the leak only one entity could provide the support.
After the leak, anyone can.
Prices would adapt to the reality, and the original vendor would have a hard time demanding the rates they are used to when suddenly faced with competition. Especially competition that kept changes open, which instills more confidence in consumers of the software.
That being said, right to repair goes hand in hand with the abolition of IP to resolve these edge cases. The problem of not providing the manual to your distributed invention goes far beyond just intellectual property, and is largely an independent issue, but good right to repair legislation is all encompassing, and is a consumer protection that naturally fits with IP-less software as well.