Passenger aircraft dedicated purely to cargo operations have played an important role during the pandemic in delivering critical humanitarian and commercial supplies, as well as generating revenue for cash-strapped airlines when travel plummeted.
Most airlines used the bottom half of airplanes for cargo, where it normally shares space with baggage, but some added extra capacity by storing light shipments in the passenger cabin and even removing seats to allow for full floor loading.
The economics...
https://www.freightwaves.com/news/cargo-in-cabin-innovation-remains-popular-for-some-airlines