The reason Shakespeare's plays are set in "foreign lands," or historical periods, was because that was what was considered interesting and worth hearing about. In 1600, hearing what happened in Stratford in 1600 just wasn't an appealing topic. But, apart from some superficial details, all these plays could have been set in London.
Take Hamlet. The author knew a few place names, a few Danish names, the fact Denmark had an elective monarchy. Are there any other details specific to Denmark? I don't know of a single one.
Besides, the way Shakespeare wrote was virtually a fingerprint. Oxford could not write like that.
There are things in the plays that could only have been known to a member of the de Vere family. No possibility that the fellow from Oxford would have known or had any access.
Also, the knowledge of foreign lands is quite a bit deeper than you contend. Certain geographic and specific details were in the plays that could have only been obtained by someone who had actually traveled there.
Authors through their works are also their autobiographers. There’s no hint whatever of any autobiography had the Stratford Will written them.
Applying Occam’s Razor, why would Shakespeare not write about Stratford or even allude to it, or write about the Court and foreign lands? The question answers itself.