Actual estimates for the total number if illegal migrants (including children) in the UK top out at around 800,000. Yet the commenter above said that your government was paying to house and feed "millions" of them. Last we checked, "milions" means >= 2,000,000.
Do you still think that what the commenter is saying "actually tends to be the case" in the UK?
How about you look up how many refugees European nations are paying to house vs getting emotional and changing the goalposts. I suspect the number is not millions, but this does not include medical care or other humanitarian care.
The GBP/EURO/USD spent is in the billions and the cost was the premise, not necessarily the number of people. If OP exaggerated, correct it and move on to the substance of the argument. It doesn’t make their entire post insipid (your words)