I have been working for the same company for more than five years and I understand 1/20th of what is communicated in meetings with more than 10 people attending

I have been working for the same company for more than five years and I understand 1/20th of what is communicated in meetings with more than 10 people attending. The company (legacy tech) I work for appears to be quite bad at communication and not welcoming, looking at facts and not at manifestos of intents, to professionals who are not coming from the company's core domain. I don't have impostor syndrome, I am overall a mere impostor.