Roughing the passer tends to get called very closely to the letter of the rule for more established quarterbacks and much less closely for younger quarterbacks.
Historically good offensive teams also get more benefit of the doubt when it comes to defensive holding and pass interference.
https://www.nflpenalties.com/roughing-the-passer-by-qb.php?view=allFor this year, here are the RTP calls by quarterback:
Goff (28) - 6 RTP calls
Geno (32), Cousins (34) - 5
Brissett (30), Tannehill (34), Wilson (34) - 4
Herbert (24), Burrow (26), Mariota (29), Allen (26), Rodgers (38) - 3
Hurts (24), Trubisky (28), Garoppolo (31), Mayfield (27), Prescott (29),
Mahomes (27), Dalton (35), Wentz (30),
Brady (45), Stafford (35) - 2
Ryan (37), Carr (31), Watson (27), Lamar (26), Henne (37), D. Jones (25), Colt McCoy (36), Taysom Hill (32) - 1
Mahomes and Brady with only 2 each hurts the narrative.
The average age of starting QBs this year was about 28.5. If we add up all the ages of all the RTP calls (i.e. 28x6 for Goff + 32x5 for Geno + 34x5 for Kirk and so on,) and divide that by the total number of RTP calls (71), we get 30.8. That's just a two year gap that can easily be explained by older quarterbacks simply being less mobile, and therefore easier to sack, and therefore likely to be sacked more often, and therefore likely to get more RTP calls because there is more potential for illegal sacks.
[/quote]
It's not just quantity. QBs on worse teams are going to get hit a lot more, so their RTP calls should be higher.