Eurostar runs a direct route, with passport control in Amsterdam. But looking at any link from Europe to London that isn’t directly served by Eurostar (i.e. any city except Paris, Amsterdam, Brussels) is going to suck.
Depends what you optimize for. I used to travel from Germany to London and had to change in Brussels. Yes you have to wait a bit, but not like at an airport. The walking distances and wait times are very small and the trains connect timewise so it is fairly stress free.
If you want to play it super save, you can stop for a good meal in Brussels as you are taking a break in the middle of a city, rather than hanging around in an airport.
I've taken Eurostar from London and changed in Paris for Grenoble and Brussels for Amsterdam (before the direct train.) It was completely fine. No different from any other train journey with a change.
I think it may have taken a while to get from Brussels to Amsterdam because that line hadn't yet been upgraded at the time but the journey time wasn't far off what it would have been getting to and flying from Heathrow/Gatwick/Stansted.
> Amsterdam to London
Eurostar runs a direct route, with passport control in Amsterdam. But looking at any link from Europe to London that isn’t directly served by Eurostar (i.e. any city except Paris, Amsterdam, Brussels) is going to suck.