I get the point : it's a scary proposition to have 'hacked' solutions to life-and-death medical struggles that have not yet had the time to be properly vetted for errors or bugs..
BUT
1) Most invention came about the same way, with a rough idea of the goal while attempting to use off-the-shelf/available techniques to attain it.
2) The COVID-19 pandemic was out-of-the-ordinary. If truly worst had come to the worst and there was a total break-down of society and medical care, things like 3d printers and old vacuum parts could have been appropriately re-engineered into appropriate medical care devices by those with the professional know-how to do so.
In other words : even if a "3d printed ventilator", for the sake of argument, is a somewhat hazardous idea in the hands of non-professionals, in the event of cataclysmic world-collapse i'd rather there be , even if simple and preliminary, a mediocre set of tools available for professionals to continue their work where possible.
In my opinion the benefit of these designs being available outweighs the disadvantage that Joe-Bob down the road may try to practice self-tracheostomy procedures.
>It was telling when you didn't see established ventilator makers coming up with their own ad hoc cheap-o designs...
the only thing that tells me is that the profit margins weren't 'right enough' to interest large corporate backers into helping -- especially during a time of economic recess and beginning of thrift strategies from the worlds' corporations in expectation of economic problems down the line until the pandemic is over.
The British NHS pay Mercedes F1 for 10,000 units of some whizz-bang CPAP machine during the pandemic.[0] CPAP machines certainly aren't ventilators, but Mercedes F1 certainly isn't an established ventilator maker, either.
https://www.motorsportweek.com/2020/05/08/mercedes-designed-...
"But something is better than nothing" isn't actually true in a lot of medical situations.
It was kinda terrifying the idea that we'd run through COVID with hordes of people hooked up to equipment someone came up with by dorking with a 3D printer and some old parts from a vacuum...
It was telling when you didn't see established ventilator makers coming up with their own ad hoc cheap-o designs... much like you didn't see Theranos's competitors make wild claims of their own similar device ... probably for reasons.