I tend to agree with you but maybe they don't practice it as much as we might suspect. I just can't believe Lamar is that blatantly inaccurate on those passes. Makes no sense to me at all.
There were accuracy concerns for Jackson coming out of college. He did improve year over year but his career comp % at Louisville was 57% and if I recall correctly, against top 25 teams he was under 50%. You can attribute some of that to lesser talented receivers dropping more passes but it could be that this is just Lamar Jackson as a passer. When you see his inconsistent mechanics and his propensity to go to the sidearm sling when it's not needed, you can understand why the inconsistency exists.