This. People lose sight of the fact that it's a 162 game season. That is a REALLY long season. Nearly every team, every season, goes through stretches where they look very good, and stretches where they look very bad. If you start throwing tantrums about how pathetic they are when they're going through a bad stretch, you're probably going to look pretty silly when they go through a good stretch. If you start declaring them "legit contenders" when they're in the midst of a good stretch, you're probably going to look pretty silly when they inevitably come back down to earth.
While the past 20 or so games has been awesome, and super fun to watch, it's almost certainly not sustainable. I think this team might be a contender for a wildcard spot, but they aren't winning the division. The Astros are just a straight up better team, and it'd be awfully difficult to make up 12 games and surpass a superior team to take the division. And it's not like the Astros haven't been playing well. We're 9-1 over our last 10, which is fantastic, but the Astros are 8-2 over their last 10. Pretty difficult to make up ground if going 9-1 is only gaining you 1 game in the standings.
I mean, it's sports. Sometimes shocking, amazing things happen. You never know. Regardless, at least this team has been fun to watch lately, and as a lifelong Mariners fan, that's about all I can really hope for.