I started experimenting with LWC and ran into this problem. What I did in VSC: - Create Project with manifest; - Authorize an Org; - Create Lightning Web Component; - Create Scratch Org and assigned it by default; I want to do "SFDX: Deploy Source to Org", but I can't find it. What could be the problem?
As of today (12.09.2021) my observation is that Deploy option in context menu depends to what kind of org you are connected/authorized to (which one is set as a default one).
If it is a sandbox -> You will have a deploy option available. If it will be a scratch org it will be covered by a SFDX: Push sources to the scratch org. I believe that plugin developers assumed that if someone is connected to the Scratch org only push would be used which theoretically should always be sufficient, but sometimes there are some use cases when it would be great to have Deploy option in context menu.
Be aware that deploy do not track changes like push
This could happen, if the default org is not set properly or more likely, the extension not activated yet.
Ensure that the connector logo appears at the bottom toolbar of VSCode and right-click again to see if SFDX options appear.
If restarting VCode (which should activate the extension) does not solve the problem, try authorizing the org again.