Bellingcat have done all kinds of investigations, including some which embarrass or implicate in war crimes governments like that of Ethiopia, Chad, and Cameroon who are US allies.
Here's another example, which highlights the lax security of US troops guarding nuclear weapons in Europe, and which strengthens the hands of activists campaigning for European governments to disallow those agreements: https://www.bellingcat.com/news/2021/05/28/us-soldiers-expos...
However, it's important to emphasise that a group can have a singular focus area and still be independent. Its researchers all have their own personal interest areas and areas of expertise (esp. in language), which drives the kinds of things they focus on. As long as nobody is directing them, and so far nobody has provided convincing evidence of that, it's not something you can rely on to prove bias. A smoking gun would be if it emerged that they actually worked on something that would embarrass the US or UK and then covered it up.
Are they pawns for the West? Maybe. But we need better evidence than this to make that a believable case.
Wikileaks I believe was accused for instance of actually having damaging documents on Russia and deciding not to release them for some reason. It was an active decision they made despite having the means, and went against their professed claim of not holding back.