Everyone knows someone who lived in a country for five years and never got past ordering coffee. Immersion is a huge advantage and it is not a method. Living somewhere supplies opportunity; it does not supply practice, and the two are easy to confuse.
A day abroad can contain almost no target language
Work in your own language, friends from home, a phone full of your own media, and shops where the whole transaction is six words. It is entirely possible to spend a year like this. Count the minutes you actually spoke the language yesterday. For most people who have moved, the number is far lower than they assume.
Immersion gives you exposure, not production
Being surrounded by a language builds listening comprehension and a feel for rhythm. Neither converts into speaking on its own — you still have to produce. This is why people who have lived somewhere for years often understand everything and answer in English. The input arrived; the output never did.
Build the situations deliberately
Pick recurring interactions and commit to doing them in the language: the same café, the same shop, the neighbour, a class in something unrelated like cooking or a sport. A weekly obligation where the language is the only option beats unlimited optional opportunity, every time.
Protect the first six months
The habits you form on arrival tend to become permanent. If you spend the first half year in an expatriate circle, that circle is usually still your life three years later. Front-load the discomfort. It is a bad six months and a much better decade.
Moving abroad multiplies the value of practice; it does not replace it. Decide in advance where the language is compulsory, and immersion will do the rest.