Aye anyone who thinks the seeding system is fair are deluding themselves
As a general rule it keeps the strongest and most influential sides at the top as they consistently get easier opponents when it comes not only to qualifying but also the group stages at the major tournaments.
Occasionally a team will see the rise of a "golden generation" or a player on the level of Gareth Bale or Ibrahimovic who can single handedly drag the rest of their side up to a new level however those sides usually inevitably fall back down to "where they belong"
Of course there are some sides who do game the system, was it I think Switzerland who took advantage of international friendly windows for several years to only arrange games against weak opponents to bolster their FIFA world rankings? Friendly matches don't give as much ranking coefficient as competitive games but they do count.