I never trust Google's targeting and always try and negative where possible.
Location targeting in Google Ads is a powerful tool that can help you make the most of your budget and reach the people who are most likely to buy your product or service.
It can target ads to specific countries, regions, or cities. You can also use it to exclude locations where you don't want your ad to appear. For example, if you only sell products in the UK, you can use location targeting to ensure your ad only appears in the UK and can also use it to exclude locations where you know your ad won't be relevant, such as other countries or regions.
Go to the Campaign -> Locations -> Excluded
Click Edit locations
Tick Add locations in bulk then paste the list in and click Search
Then you can Exclude all
And the map should go red to show the excluded countries
If you have a lot of campaigns then it's much quicker to copy paste in the Editor.
I add the negative list to one campaign online, then open up the Google Ads Editor and copy the list to the other campaigns.
Select a campaign with the negative locations and select and Copy them all
Then Paste into the other campaigns