The meat-packing plants were well-designed given their constraints, but this coronavirus was unanticipated, and creating production facilities with more protections against this will take a lot of time and money. These new facilities would also use much more energy (roughly proportional to the increase in area required), so you have to ask whether those costs would be worth incurring to help with the next (hypothetical) outbreak. It's too late to build new facilities for this one.
It's good to fight for better working conditions for all, but not without remembering the lowest-end of the wage ladder.
(Which isn't to be interpreted as an argument against minimum wage increases, but rather that there needs to be an on-ramp for those who didn't grow up with privilege)
[1]https://www.cbc.ca/news/canada/calgary/3rd-covid-19-death-ca...
[2]https://www.cbc.ca/news/canada/calgary/cargill-alberta-covid...
[3]https://www.theglobeandmail.com/canada/alberta/article-alber...
[4]https://www.cbc.ca/news/canada/calgary/covid-outbreak-cargil...