They could indeed - the problem then becomes that those migrants often go home afterwards and work for a single season. The benefit of this low paid work to them is simple - it is economically advantageous due to the exchange rate. They are earning more in real profit than any Brit ever would and they have homes abroad to return to.

If I were to leave my house to take up a full-time job somewhere else for a single season, I would have to sublet (which is breaking most rental contracts) or I would have to continue to pay rent over the time I was working. That might make this sort of job viable for people who live at home and who want to join the workforce (older teens/early twenties) but those people all have dreams of becoming Instagram influencers and are not easily persuaded into roles they think are beneath them.

Problems problems problems. :o)