Tier Lists don't matter for advanced players either. Players at that level can keep in mind what their personal hard matchups are already, being you know, human beings capable of memory capacity and being in posesion of the ability to learn from mistakes and pick up patterns ("Oh, I seem to always lose against Hazama when I'm Tager, and nothing I've explored seems to make the match any easier; I should look out for Hazamas and find some new strategy or character to deal with this problem"). You'll never see a GF winner saying anything like "Yeah, I thought for sure I was going to lose, but then I remembered that he was using a low tier character! Thanks to that wonderful tier list, I was able to take the set!"
you won't see a GF winner saying "Yeah, I thought for sure that my Chun Li was going to lose, but then I remembered that he was using Sean!" either, hahah
(there are other examples of dominant characters/teams such as MvsC2's Magneto/Sentinel/Storm, Garou's Kevin Ryan, KoF 2003's Duo Lon, ST's Akuma, I heard that the latter, at least in Japan, requires the user to input the unlock code correctly for every match he's in, else he's instantly removed from the tournament. Still, he's.. Akuma tier in that game.)
Fun fact: low-tier characters can, at times, be used for the sole purpose of putting your opponent off (read more
here).
>> Players at that level can keep in mind what their personal hard matchups are already, being you know, human beings capable of memory capacity and being in posesion of the ability to learn from mistakes and pick up patterns
if someone feels like their favorite character's moveset/attributes fits their playstyle better, it's okay to try to find a way around their matchup problem. It's good when/if the game gives them such a possibility (meaning that the character doesn't suffer as much from specific matchups). It's not good when/if changing your character is the least effort for the same (or better) results in that specific matchup, balance-wise. Having too many problems against too many characters (such as lack of resources for creating openings or taking good enough advantage of them -- basically, having to work way harder than your opponent) is, generally speaking, what makes a low-tier character, a low-tier character.
>> Tier Lists don't matter for advanced players either.
more often than not, tier lists reflect which characters have the highest chances at winning tournaments or placing well. (I'd say, "which characters have the highest chance of winning when used well")
tier lists are subject to changes when games receive updates, or the players discover new technology (like your example; if said Tager player is able to research or discover a new way to beat Hazama's tactics, it's an improvement in the Tager's tech/repertoire), and then are remade after enough game theory has developed. They're not set in stone (you don't say you won because of the tier list), but using a low-tier character without being aware of its deficiencies or without having something new to show (new technology, such as a new combo, a new setup, a new way to counter or a new frametrap/mixup, etc.) doesn't excuse you from losing. That's the equivalent of purposedly lowering your winning chances. (some people joke about people who're biased against high-tier characters, saying things like "hello, I'm a low-tier user. If you win, you're a tier-whore; if you lose, you're a n00b/I'm awesome.")
As a final consideration, it's acceptable to have matchup imbalances; it's not, though, to have nearly-useless characters (useless tier) or to have dominant characters (overpowered tier) that forces every other player to use said dominant characters (or slightly worse ones) to have just as high chances of winning. Both of these tiers contribute for lowering the viability of a number of characters or character-specific resources in a character roster, and lowering the depth of the game.
