There aren't enough ICU beds or nurses to go around by several orders of magnitude, so 3D printing isn't a panacea to anything. It doesn't matter if there were an unlimited supply of FDA-approved ventilators and ECMOs, there aren't enough respiratory therapists, ICU nurses or perfusionists to go around.
My strategy is far simpler. I have one elder to take care of who will be self-isolating for 3-6 months. Not getting sick is superior to relying on a nonexistent, failing medical system on the verge of collapse.
I agree with you that not getting sick is the topmost priority.
The open source ventilator efforts are well-meaning but have a high chance of being close to useless, especiallly without trained medics to go with them, and I agree with others that they might make things worse. We really do need to focus on preventing and reducing transmission first and foremost.
Unfortunately, there remains the question of what are you going to do if your loved one gets sick despite your best effort to prevent it.
The numbers around at the moment suggest there will still be too many of these happening for the hospitals.
Also, unfortunately, many vulnerable people don't have the realistic option to self-isolate.
For example anyone who lives in a cramped house-share and has an existing respiratory condition (asthma etc) is vulnerable, regardless of age, and cannot rely on self-isolation to stay safe unless everyone in the shared house isolates as well. Which they will not.
There are a lot of people in that kind of situation.
Similarly anyone who has a vulnerable partner, in a place that has no spare room for them to isolate in, and at least one of you still has to go out to work to pay for rent and food.
Not getting sick is by far the best option, and preventing transmission is by far the most important thing to do. But unfortunately, we have to explore all realistic alternatives for when that doesn't work, even if those alternatives are a bit desparate and may not help.
One possibility that may be of intermediate use is efforts at building kit that hospitals might be able to use when the proper kit has run out. In that situation there will be trained medics but insufficient equipment. I'm not sure but I think it plausible that an open source ventilator project, especially a well-run one, might be able to help in that sitution.
My strategy is far simpler. I have one elder to take care of who will be self-isolating for 3-6 months. Not getting sick is superior to relying on a nonexistent, failing medical system on the verge of collapse.