West Ham have been having an extraordinary season. But at this stage of the championship, I think it will be very difficult for them to reach 4th place. Mathematically it's still possible, but it would be necessary for the teams in front to start losing several games.
In the best case scenario, they may even manage to stay in 6th place, if Man United continues to play very irregular games.
Based on the performance of the team that West Ham has so far, I am not sure that they will be a candidate to enter the Europa League group stage next season or a team to qualify for the European Conference League. Although mathematically it is still possible, but Manchester United and Tottenham have a bigger chance than West Ham.
Arsenal and Tottenham so far will still be competing for a ticket to the Champions League next season which Arsenal have a good chance to prove this season. Arsenal have improved quite well this season although they were very unconvincing at the start of the season. If Arsenal are capable, then this is the success the fans expect from Arteta.