I am currently having much fun in World of Tanks, working on the two German tank destroyer lines, still at low tier. One of the fundamental problems of WoT is that it gets worse when you progress. There is no separation of players by skill at all, any skill level can play battles at any tier in random battles. While there are experienced players "seal clubbing" in low tiers, the highest concentration of experienced players is in the high tiers. So while Wargaming will happily sell you tier 8+ premium tanks or make your progress into the high tiers easier with Top of the Tree events, actually playing in tier 10 games against people who have played for years and are so much better than you isn't much fun. I'm not even playing my recently acquired French heavy tier 10 tank anymore, although I would still get extra experience and bonuses for doing so until the end of the month.

While World of Tanks does have "raid-like" content for more experienced players, that content is only accessible in groups and not sufficiently attractive to keep the veterans out of random battles. For both official xp/credits and unofficial WN8 rating, a point of damage is a point of damage, regardless of whether the tank on the receiving end was a noob playing a tank two tiers below you, or whether there was actually a challenge involved in the fight. Thus if you are an experienced player, your best bet is to play your tier 10 tank in random battles, as you always will be top tier. Less experienced players with tier 10 tanks will still be top tier, but won't actually do so well against the veterans. So for me the best strategy is to play tank lines only until tier 7, which even with +2 matchmaking will never see tier 10 tanks.

Of course that means that in a game with a significant part about progress, gaining xp and tiers in tech trees, I don't even want to progress beyond a certain point. Which makes that progress less interesting than in other games. Even if you didn't want to raid, you still would want to reach the level cap in World of Warcraft. Not so in World of Tanks. For the players that has the positive side that progressing to tier 7 is relatively fast, and the much slower progress to tier 10 is better skipped anyway. However for Wargaming that concept isn't so attractive, because what they are actually selling to paying customers is faster progress. If too many average players would realize that the top tiers are not worth getting to, they would stop paying for faster progress there.

One weird side effect is that I care very little about the progress I made before, my tier 8 to 10 tanks. If for some reason my account was hacked or a server bug would erase all my progress, I wouldn't even shed a tear. I could have pretty much the same fun with a brand new account.

From a game design point of view, that isn't ideal. If I had a say in design, I would do two things: Make rewards dependent on the tier of tank you damaged, possibly even on the rank of the player driving that tank, to make bottom feeding less attractive. And create some more attractive "end game content", like random battles for people with a certain personal rating or number of battles played, to keep the players with years of experience separate from the new and average players. That would give the experienced players more of a challenge, and open up more interesting progress for the average player.