Training an ICU nurse takes about 5 years. The only realistic option during the pandemic would be to encourage immigration of ICU nurses from poorer countries, but that just moves the problem elsewhere.
I think that training people to handle 90% of the issues you see in Covid-related illnesses could be done relatively quickly, if we wanted to do that. The ICU bed shortage really refers to a ICU-staff shortage, and anything we could do to relieve that burden would be a good thing.
Look at the sheer difference in numbers of healthcare professionals between America and Cuba. If they can do it even after decades of cruel and unusual sanctions, we sure as fuck can too.