When I am looking for info, I prefer to start in my home country. I have set the toggle to Canada, but American sites keep coming up first. What good is the toggle if it doesn't limit searches?
Where is this toggle? Ive never seen one as part of Firefox, only as a part of search engines.
If your problem is with the option of your search engine, you may wish to consider discussing it with whoever operates said search engine (since Mozilla doesnt operate their own search engine iirc). As far as i know, such options are not hard filters in that they do not decide relevance, only modify it.
That said, filtering websites by country would be quite challenging to implement reliably, since most websites dont signal this information in a machine-readable manner.
The possible things you could filter on include:
IP address country assignment: many websites are hosted on cloud servers outside the country of the organisation that owns the website (especially when multiple redundant servers around the world are used to reduce latency)
Top-level domain: Not all websites use ccTLDs, and out of the ones that do some use them for "vanity domains" (where the TLD is picked to complete a word e.g. youtu.be)
Hard-coded list: Would be impossible to maintain at scale
DNS LOC records: Intended for server location (see "IP address country assignment"), plus very few DNS providers support setting this. Even if you are a website admin and your DNS provider supports this, you aren't likely to implement it since it has little practical use.
Machine analysis of website content: Computers aren't great at this stuff (assuming the website even has info about who is behind it) and can easily get it wrong