Follow-on to my post awhile back on things we are all thankful have been fixed in the game, at least since I started playing in August 2013.
FAIL PLATOONS–now impossible to form! Back in the day, there was nothing more frustrating than loading into a high tier match and seeing that some d0uch3bag had brought along one or two tier 1s, which meant your team was effectively playing with that many fewer tanks.
EQUIPMENT–diversified and price adjusted! It wasn't long ago when every tank had one agreed-upon "best" loadout, because equipment was so restricted (and good equipment even more so). Now many tanks have honest-to-goodness builds, and kitting out a low-tier doesn't cost 3-5x the price of the vehicle!
SMALL CONSUMABLES–now recharge on a timer! This greatly decreased the capability gap between richer players and those less so, which is always good.
CREW AND VEHICLE GRINDS–shortened with Crew Books, Boosters, and Blueprints! No longer does it take hundreds of battles to get a good crew or to get through a bad vehicle or two, just use your resources wisely.
ILLEGAL BOTS–improved! Indirectly. When WG removed all rewards for AFKing through a battle, the bot sellers were forced to add actual motion and firing abilities to their get-me-to-tier-10-without-actually-having-to-learn-the-game programs. Now they're largely indistinguishable from bad players.
KV-1S–nerfed! Used to be an IS a tier lower and with slightly worse armor and HP, and consequently obsoleted every other battle tank at tier 6 (and competed with some 7s). The official wiki even admitted as much.
WAFFENTRAGER AUF E 100–removed! For most, this wasn't fun to play or play against–the monstrous magazine could turn a single mistake from its opponent into an early death. But everyone, especially arty, prioritized the huge, unarmored turret with HE, often ending its game after it fired just a partial magazine.
That should be all the big improvements that I've personally experienced. Maybe I'll make a third post for improvements from before mid-2013 (Great Arty Nerf, +-3/4 MM removed, tier 5 KV with 152mm, etc).
Source: https://www.reddit.com/r/WorldofTanks/comments/quttqi/ways_the_game_has_improved_part_2/