Even though Barzal has said on multiple occasions, including in Elliott Friedman's 32 Thoughts podcast, how he believes in the Islanders' defensive responsibility being a key to winning in the NHL, he is not strong in the defensive end himself. Obviously, that is not as big of a problem when the rest of the team is playing a two-way game, but he leaves a lot to be desired when backchecking or forechecking in the tight areas.
Barzal is not by any means a shoot-first player, and that is fine, but every so often, he needs to take the shots he is given. He will pass up a wide-open shot on many occasions to make the extra pass, even if the opposing defense is covering the other Isles well. His one-timer that we've seen from time to time is also very inaccurate. When he is close to the goal, his wrist shot can make goalies pay, and most Islanders fans would like to see him be a little more selfish sometimes.
Up until 2021-22, Barzal had not missed significant time due to injury. The 24 games he missed were hard to watch sometimes for an already lackluster offense and brutal power play. Barzal looked a little out of sorts when he hopped straight into playoff hockey against the physical Canes, but his return certainly didn't hurt the team either, as he scored in Games 2 and 5. If the Islanders are to put up better offensive and power-play numbers this season, a healthy Barzal that excels alongside Horvat is most likely way it happens.