Hi Peter,
I understand your menu options are very different from the support videos displaying. Sometimes the reason for options limited is that some related features have not been activated by users.
Based on my experience, users can resize image not only by dragging, but also manually typing the value after inserted by default. No matter when editing public-facing website or team site.
When editing public-facing website, select the image-> click Format under Image Tools navigation->type the value in Size section.
When editing team site, select the image-> click Design under Picture Tools navigation-> type the value in Size section.
Please provide the screenshots by performing the following steps.
1. Click Use rich formatting.
2. Clicking Insert Image icon.
3. Browse the image location and click Insert.
4. Click Post.
If you have other options limited, please feel free to let us know. It’s always our pleasure to be of assistance.
Thanks,
Maggie Li