Justin Fields has the worst offensive supporting cast in the league and it's not particularly close.
Mahomes 1st season starting, he had Tyreek Hill, Travis Kelce, Kareem Hunt, Sammy Watkins, Spencer Ware (year after almost 1k rushing yds), Chris Conley (basically a more productive Pringle, had 5 tds), and a total of 7 guys who had more TD catches than anyone else on the Bears roster did last season (with the exception of Mooney).
Burrow has Jamar Chase who is significantly better than anyone the Bears have at WR, Tee Higgins (more yds than Mooney, 1 fewer TD), Joe Mixon (13 rushing tds, 1200 yds), Tyler Boyd (828 yds, 5 TDs), and CJ Uzomah (493 yds, 5 TDs).
Lamar Jackson had 16 tds, 13 ints last season. His two top receiving targets were Mark Andrews (1361 yds, 9 TDs), Hollywood Brown (1008 yds, 6 TDs), Rashod Bateman (46 catches, 515 yds, 1 TD, this year already has 2 TDs and 167 yds in 2 weeks) and Sammy Watkins (394 yds, 1 TD). The Ravens ran the ball by committee with Lamar leading the way with just under 800 yds rushing and 2 running backs (Devonta Freeman and Latavius Murry) combining for 1077 yds and 7 TDs.