2 players out of a whole roster of 20+ players is not indicative of the whole rosters playing ability for the years pre & post championship. Thats just your bad opinion that holds no basis for it.
Championship teams have high turnover in the years following the win because the core players have developed, played and matured there for years and only get older. In case you decided to willingly forget, its kind of difficult for any athlete healthy or otherwise to play and produce at a high level when theyre older vs their prime in pro sports. If you ever even decided to look at the numbers instead of blaming players for their personal time off, youd see that the average age of teams who win are older. But that wouldnt fit with your bad narrative so of course you wouldnt.