This doesn't read like Imposter Syndrome, but rather not being aligned with culture/way of working of your current company/team. I've been in that situation and

This doesn't read like Imposter Syndrome, but rather not being aligned with culture/way of working of your current company/team. I've been in that situation and tried working harder. It just made the problem bigger. If you have a good leader that you trust in your company, have this conversation with him/her. Approach this in a way of how you can be of more value, rather than criticizing the team.