2. Not addressing the tight end position
The Dolphins watched former starting tight end Mike Gesicki leave via free agency, signing with the New England Patriots, and leaving them with a gaping hole at the position. Gesicki was, at times, under-utilized considering his skill set. The Dolphins don't use the tight end position a whole lot, though, so on one hand it made sense.
But, the drop-off in talent after Gesicki left was a big one. Miami didn't do much to address the tight end room after Gesicki made his way out, leaving Durham Smythe as the team's de facto starter. Miami did sign veteran free agent and former Denver Bronco, Eric Saubert, to come in and likely play a backup role.
The Dolphins also drafted Elijah Higgins out of Stanford in the sixth round of the draft, but to say that he's going to come in and light the world on fire would be silly. Tight ends already take a while to develop in today's NFL, so to expect Higgins to make a huge impact right away is foolish thinking.
A couple of veterans are out there in the free agent pool, and the Dolphins could use one as they're a win-now team. Cameron Brate and Marcedes Lewis are still available, with the former being more of a receiver and Lewis being one of the best blocking tight ends that's ever played.