David Warner was definitely the best opener for Australia. The Australian batsman's ability to play in Test ODI and T23 format was excellent. He retired from Test cricket while in form and there are rumors that he will start his next career as a team coach. However, he has said that he will become a coach only if his wife allows him to become a coach. As much as David Warner has excelled in his career as a player, he will excel in his career as a coach. If he chooses coaching career then maybe Australia team can keep him as batting coach or as assistant coach but it's a matter of time before he has to decide to get license before he can take charge of a team.
Warner has retired from Test and ODI but will continue to play T20 cricket, as per my knowledge. He is no doubt one of the greatest opening batsmen produced in the history that can play test, ODI and T20 format. He play test as genuine test player while in T20I he is a solid hitter like a young player. Aussies have a good domestic setup and they will produce some other great opener to replace Warner.
I think David warner ready to play champion trophy 2025 in ODI tournament in Pakistan if Australian cricket board select him. The decisin of retirement from test cricket is good beacuse now they will focus on T20 and leagues cricket short format. David Warner is very dangerous against Pakistan in ODI ans Test cricket. In last test match against Pakistan David Warner scored amazing fifty scores 57 runa in 75 balls out by Sajid khan and played an important role in victory of Australian against Pakistan.