In this case presumably the main difference is not PowerShell vs. bash but iwr vs. wget? Because I think this is roughly equally bad (untested):

    for page in {1..1119}; do
        iwr "https://codex-atlanticus.ambrosiana.it/assets/2000/000R-$page.jpg" -OutFile "000R-$page.jpg"
        iwr "https://codex-atlanticus.ambrosiana.it/assets/2000/000V-$page.jpg" -OutFile "000V-$page.jpg"
    done

Also until recently bash didn't have {42..53} syntax. You had to use `seq`. There was an alternative name for `seq` in Unix Power Tools, `jot`, because it wasn't standard: https://docstore.mik.ua/orelly/unix/upt/ch45_11.htm. This section was by ORA author and sysadmin Linda Mui (https://www.oreilly.com/pub/au/268), but I don't know if she wrote `jot` or just popularized it.