The point is that the migrants could stop in France or Germany rather than cross the channel, but do not choose to do so.
Those who try to cross the Channel planned to come to the UK since the beginning of their journey, mostly for cultural reasons.
The few refugees that choose to cross the Channel do it because they have relatives or friends in the U.K. and take significant risks to cross the channel.
Considering the part of the populations that keeps voting for xenophobic Tories, that the whole country threw a hissy fit about immigration in 2016 and has been hardening its stance by the day since, and the pile of scandals à la Windrush, the reality is somewhat more nuanced than that.
> They also speak English, which will also be a driving force from certain countries.
Yes, this is an important motivation. There is also the aura from nearby commonwealth countries. The UK used to be good at building soft power.