Yes, of course, it will be very difficult because big teams always prepare and bring in excellent recruits. For Arsenal, just like last season, they should set specific goals in the Champions League or Premier League. I understand that the current position and strength of the team are not at the level of the illusion of being able to hold all titles even though in theory, that is still within reach. Arsenal is currently lacking a real goalscoring striker, they need to add one in this summer transfer window. Arteta's tactical innovations have led to Arsenal's recent successes. And if Arteta can continue to innovate and think of new ways to beat teams, there's no reason why the Gunners can't win this season.
Arsenal have managed to play consistently in the last two seasons. This shows that Arteta has succeeded in building a solid squad. Arsenal has a big chance to win the EPL next season. They seem to have been unlucky in the last two seasons. I'm not saying Arsenal are inconsistent because of the fact that they don't have much of a points difference from Manchester City. They were just unlucky when they got bad results in several important matches at the end of the season.
But I'm not sure about their chances in the Champions League. Arsenal is one of the best in England but in the UCL the competition becomes more difficult and there are many teams that have also improvised. Real Madrid and City are still the strongest candidates in the UCL next season. So far I see no other team that has the same level.