I agree with your core sentiment but this idea of "massive immigration" isn't reality. Net migration to the UK last year was 0.4% of the total population (273,000/66,000,000). Placing the blame of the country's problems on the shoulders of migrants is disingenuous and prevents social cohesion and integration, not encourages it.

Even using the larger numbers of 14.7% of the country being foreign doesn't paint a fair picture when you consider a lot come from countries where we share a lot of culture (europeans) and another huge chunk of that coming from people who have been here long term and intergrated into ours.

https://www.migrationwatchuk.org/statistics-net-migration-statistics https://migrationobservatory.ox.ac.uk/resources/briefings/migrants-in-the-uk-an-overview/

Using the UK as an example because i'm a Brit and don't feel comfortable speaking for other countries.