That's fair.
To answer both your questions, it really depends on the scenario.
The fact is, no matter if you're playing a fighting game, an MMORPG, a TCG or a Wargame, there will always be options that are straight up better than others. Some people play to win, so they go for those top-tier options. And that's fine, but you can't assume that just because you're playing top tier you should win. You also shouldn't look down on people who choose not to play top tier, because sometimes they've got some aces up their sleeves you can't expect.
And that brings me around to your other question about being fixated on tiers in general. It's fine to monitor the tier list and keep track of how well each option is doing, but don't let it give you tunnel vision. I've played a lot of games competitively, or at least on a hardcore level. Smash, Yu-Gi-Oh, Pokemon, the Pokemon TCG, Magic, World of Warcraft, I could go on for a while. But the point is that there's always that one guy who is so fixated on the meta, on playing whatever is top tier and focusing on the options that are also top tier that he doesn't think beyond that. Said guy usually gets blindsided by people using rogue options that he can't anticipate or think to counter.
tl;dr version: It's okay to play and monitor the meta, but don't assume that playing top-tier should net you easy wins or that you can't lose to somebody playing something else.