The phrase "effectively cut off" is correct and can be used in written English in many contexts.
For example, "During the pandemic, large gatherings have been effectively cut off."
The channel was effectively cut off to traffic.
The town of Braunton in north Devon was effectively cut off, with homes and shops under water, after the River Caen burst its banks.
With the American, British and Canadian actions, he said Iran was effectively cut off "from three of the world's largest financial sectors".
Weeks earlier, he had promised that his work would in no way interfere with that of two colleagues, whom he effectively cut off at the pass.
Yi's victories off the southern coast effectively cut off the Japanese troops in Korea from supplies and reinforcements and prevented the Japanese from pressing their initial advantage.
While Johnny's cognitive functions escaped serious damage, the orders coming from his brain were effectively cut off from the rest of his body.
Algiers residents said the city centre was effectively cut off from the suburbs yesterday, but that some schools, shops, government offices, banks and other businesses had reopened.
In July, the US effectively cut off five Russian financial groups – VTB Bank, Gazprombank, Bank of Moscow VEB and Russian Agriculture Bank – from US equity and debt markets.
A large market for the local merchants will be effectively cut off due to the tremendous inconvenience of having to use the Canal Street Station for transportation.
He had been traveling along the front lines, paying surprise visits, when the Iranian line launched an offensive and effectively cut off his position.
Joyce said failing to get halal certification would effectively cut off large export markets for Australian meat products, and warned against "picking a fight that we never needed to have".
