Hardware is hard. Really hard. You're talking about firmware, software, electronics, manufacturing, testing. Talk about full-stack development, this is true full stack development.
Peter Thiel, amongst others has complained about the very true problem of tech wanting to change the world and only doing so for bits and bytes.
He also mentions that Elon Musk is one of the few entrepreneurs that is making the jump from bytes to atoms with Tesla and SpaceX.
I believe the key to this ability to bring a startup, high pace, innovation based approach to hardware is the ability to replicate the software development process that exists today on the web.
Software is highly iterative, there are no version, you can deploy changes daily, multiple times a day. There's a reason why tech startups outpace any incumbents.
Unfortunately for the majority of time hardware has been made as versions. You have your 2014 Prius, 2015 Prius, Roomba 1, Roomba 2. This is often due to the fact that hardware manufacturing is hard and costs a ton of money/time to alter things. So most major companies don't change things year to year.
There are some great parallels between the war between Desktop "Software" and Cloud "Software". Desktop version get released yearly, cloud software gets updated daily. Its pretty clear who wins that one.
There's a reason why Slack came along and smashed competitors in the face, they use chromium, a browser emulator on the desktop that allows for daily updates without needing a user to "update" their software.
Going back to hardware, the secret to Tesla and SpaceX ability to compete with existing incumbents is their speed of innovation. The Model S does not get released every year as a new version, instead each new car that is rolled out has new features added as new features are ready.
All of a sudden features such as auto-pilot driving, ludicrous mode can be released in subsequent months instead of in a yearly cycle.
Beyond this Tesla has built in their own custom firmware/software into their car so remote updates can happen at any given time. Tesla amongst others has been able to bridge the gap of innovation from the web to hardware by allowing their engineers to continuously deploy, test and release improvements to the car via software updates.
If more hardware companies can build on this practice of speed and innovation into their manufacturing and product software, you'll see new startups blow incumbents out of the water in a matter of months simply due to the speed of their improvements.
Speed kills competition. Startups already know that. Its time to see more hardware startups take this approach and beat out their bigger competitors.