2.) Getting better separation from defensive backs
While the Bills have without a doubt become a pass-first offense, their lethal attack is only as good as receivers getting open. While Diggs is arguably the best route runner in the league, he is the type of player that defensive coordinators game plan for which includes double covering Diggs.
With the double coverage, it forces Davis and other receivers to go one-on-one with defenders and beat them down the field. This has not always been the case which limited the passing game at various times.
If you watch the Bills play on offense when they try to go through the air, Diggs can be double covered by a corner and a safety as backup and Davis sometimes fails to get separation to allow Josh Allen to make a play with his arm. No separation means no option for Allen, which means he may try to force a throw or use his legs to make a play.
As a receiver in the NFL, all that they have to do is get a step or two in front of defensive backs and quarterbacks will launch it up to gain big yardage.