I don't trust the small number of E2E US services at all. E.g., some of the companies that were/are in PRISM seem to have very convenient 'accidental' backdoors. E.g. WhatsApp doing backups on Google Drive without encryption by default on Android or Apple doing iCloud backups of iMessage that are not E2E encrypted unless you enable ADP. And even if you are wise enough to enable E2E in both cases, most people that you communicate with don't, because they use the defaults, so it's game over anyway.