It depends on where.

In places like Australia and North America — the native populations were completely erased (largely due to old-world disease) after British colonisation and thus English became the predominant language here

In the case of India — English would have been learned only by those who went to school and eventually higher education. As very few people went to school in those days — it didn’t catch up.

Macaulay-ism sought to make a class of elite people in the country who were Indian by blood but British by taste. This ended up backfiring a little though as those who led the Indian Independence movement were exactly these types of people.

That said — in former British colonies in the old-world (Africa, India, Malaysia, etc) — English still remains a key language of administration and serves as a lingua franca amongst the different ethnicities (in India — Hindi also helps serve this purpose).