For example this one is about a van which got stuck in one for two years: https://www.bbc.co.uk/news/articles/cx207jwknp5o
Or there was one in Sweden which trapped cars for 2 months: https://www.mitti.se/nyheter/fnurret-pa-psnurran--m-vill-se-... (sorry, could only find a swedish source)
It is because these kind of systems are complicated bespoke automation. When it breaks down it costs a fortune to fix it. And what can happen is that different parties (operators vs manufacture vs maintainer) gets into a contract dispute to see who is liable to pay to get it fixed. Which as you can guess can take years to play out. Meanwhile your vehicle is stuck and nobody who could is interested in spending a penny on getting it out.
In contrast to that this project is better in two ways. There are multiple robots. (or at least there really should be) So if one breaks down the other robots can still retrieve cars (albeit of course with reduced throughput). And because the storage is just a flat parking lot if all the robots give up the ghost at the same time humans can drive out the cars from the edges of the storage rows.