Not to be pedantic but the Marcus form is tiny so you can be up and running in a matter of minutes. Just take a look at what people have been saying in this topic: Marcus Bank
Same with switching energy suppliers - I’ve done this recently and it literally took no longer than 2 minutes and my bill has almost halved so I don’t think hassle comes into the equation anymore these days. As a result of spending 2 minutes of my time it has saved me hundreds of pounds per year and the same applies with interest on my savings. You’ll find that half a percent (even though Marcus is more) adds up to quite a bit and it is therefore certainly worth considering all your options instead of going the “easy route”. 