The Apple Watch has no ports, rendering it impossible to force it into a hardware recovery mode. Thankfully, Apple has finally addressed this shortcoming of Apple Watches with watchOS 8.5, which is available to download on the Watch Series 3 through Watch Series 7.
https://www.notebookcheck.net/Apple-Watch-frustration-resolved-after-nearly-7-years-with-watchOS-8-5.609110.0.html
What specifically does Recovery Mode cure?
For instance, I had a dead screen one morning and none of the various suggestions I found for curing it worked. Could Recovery Mode help with that?