Maybe an unpopular opinion, but I think Alysa deserved her victory here given the current scoring environment. The truth is that the way figure skating is scored right now just doesn't reward artistry (and even then, that's a subjective thing to judge).
Alysa put out 3 triple axels, 1 quad lutz, and every triple-triple combination backloaded. Mariah is a stunningly expressive and fluid skater, but you can only give so many points for that in figure skating. And the judges sure did, nearly maxing out her Performance/Composition/Interpretation components like she's the new Kostner. The thing is though, Alysa isn't too shabby in her own expression and performance. She still has the juniorish bliss look, but she still gives a performance and serves the choreography, all while balancing with her quasi-elements. Maybe 68 was too high, but it was a) Nationals, b) a mostly visibly clean performance, c) she really has improved leaps and bounds in her speed and expression. You would have to pull her down to 58 PCS to push her below Mariah, and if Mariah gets 75, I'm not sure Alysa would deserve 58.
Also, no hate toward Mariah, but I feel like people are overlooking her technical flaws. Her spins? Gorgeous. In fact, the US ladies (Bradie, Alysa, Karen) have technically powerful spins - well centered, fast, good positions, and flexible enough. Because they don't have the flexibility of the Russians, they don't get enough credit but their spins should be on par with the Russians given their speed and centering. Her expression? Gorgeous. However, you can only reward that so much in the PCS. I wonder if I'm looking at this wrong, but my overall impression of Mariah's jumps isn't too fantastic. She's made huge improvements, finally nailing consistent triple-triples, but her landings still look sloppy and don't always have flow coming out. A lot of her landings look muscled and barely hung on. I get incredibly nervous watching her jump, and sometimes wince at those landings ... whereas Bradie's landings tend to be solid and crisp, aside from the few UR's. You can argue Alysa's jumps aren't too great either, and I agree, but I think they are scored fairly for what they put out. Their scores should've been closer, but I think Alysa still comes out on top.
If Mariah had more technically superior jumps, I would agree with the sentiment that she was robbed the champion title, but she doesn't have enough technical firepower to make up a 21.49 BV deficit. You could argue Alysa receives generous GOE but looking at the scorecards, judges really aren't lavishing her the way people seem to think she is. Relative to what Mariah gets for her jumps, I'd say Alysa's are fair. Alysa has a lot of room for improvement, but she's bringing a lot to a sports competition and it's hard to deny her the victory given what she puts out.