You skimmed over the key point a bit. "If" tech is invented, it gets distributed faster/quicker/cheaper without patents.
If. What incentive does anyone have, large or small, to put large quantities of money into R&D work if it will give them next to no market advantage? The overlap between companies good at innovation and companies good at mass manufacturing is surprisingly small - large companies, which completely dominate manufacturing, are absolutely terrible at innovation.
A huge amount of early innovation is done by small firms and universities, which then license that technology to larger companies to produce. Modern technology developments are too complex to be done by a man in a garage. It takes teams of people years to develop better engines, better batteries, better industrial processes. If the financial support for that work is removed (which it would be without patents), it would stop.
A functioning engine or machine could be copied in weeks by a large team of engineers. What isn't seen is the years and years of iteration and lessons learned from the development of that machine. If a world without patents is not of benefit to the person creating these machines, why would they bother?
Software is a very different case to physical technology. The investment required in software is almost all labour (and so can be bootstrapped). The functionality can be provided seperate to the source code, making complete copying hard.