Qualcomm's mobile team successfully maneuvering to kill Qualcomm's ARM server group when the server group looked like it was going to become very politically powerful because it would've had the highest performance ARM server part available and had large sales lined up at FB, etc.: https://www.patreon.com/posts/20571244

MS Office killing NetDocs basically Google Docs but created in 1997: https://twitter.com/danluu/status/790599349491212288.

Also, NetMeeting (Zoom with whiteboard and stuff, '96): https://twitter.com/danluu/status/1572839354434977795?s=20