Not all games lore is handled equally. I feel when the game is based on a written IP the lore usually end up more solid. The games also usually play safe by adding (and killing) disposable characters with no real ties to big names like Vader or Gandalf.
However, when the IP is purely game-centric and just grew too big over the year with multiple writers funny thing happens. The best example which comes to my mind is Blizzard IPs which seen to have lots or "lorelols" and there is this feeling of the history being written (or rewritten) as it goes.
I can't fault someone writing a "wrong" quest line with contradictory lore when the relevant information is spread among 10+ years of games, books, and comics. That's why I take most video game lore with grains of salt no matter how official it saves a few exceptions.