Full disclosure: I lived and worked in Russia shortly after the breakup up of the FSU, married a Russian (that had previously immigrated to Canada) and, at least until the Russian Ukrainian war, traveled to Russia every few years to see family.
Now, do I belive BG is a pawn in the greater Russian/US politics? Without question.
Do I think 9+ years is harsh punishment for her crime? Yes. However, it is not an outlier in the Russian judicial system.
Do I think she was unlawfully detained? No. She was carrying banned drugs and admitted to doing so. She broke the law.
Do I think she accidentally packed the banned items. No, but that is purely speculation on my part. I know when I travel to Russia (or, any other country for that matter), all medications are packed in their original containers and I am careful not to pack any banned items. I even leave my non-THC CBD ointment at home over concerns it may trigger questions from border officials.
I have mixed views on the US government's response to BG's situation. First, I believe they are playing directly into Putin's hands. Second, we have other US citizens detained elsewhere overseas. Where is the US government response to them?