Weren't they in their van/RV? Their blog indicates they were living the van life, with occasional hiking. Lots of time was spent in campground. They didn't need a car and they weren't hitchhiking. Indeed, they were on their third vehicle, having started this lifestyle in 2014. They seem to have carried bikes on the back of their van, as well.
Are you sure they hitchhiked around Europe? In this post from 2020, they mention that they are hiking back to their motorhome. I see nothing about hitchhiking anywhere on their blog:
Just Around The Matterhorn - Verbier - DAY 23 - Photo Diary | Esther & Dan - Adventuring Together - Life, Love, Health & Travel
They discuss petrol pricing, etc and in March 2020, they discuss their views on living longterm in a small space (the van):
Lockdown Lessons From The Van: Seven Ideas For Staying Sane In A Small Space | Esther & Dan - Adventuring Together - Life, Love, Health & Travel
They discuss their 2020 travel plans, the fact that Dan is taking a guitar, etc. This article on BBC says they have no plans to change their lifestyle (and the van is discussed).
Van life: Durham couple's six years on the road (and counting)
To me, they very much seem like they are in the VanLife subculture, sometimes staying quietly and restfully at various campgrounds, in their van, throughout 2020 and before. That's how they style themselves. If they're actually hitchhiking, that's a tremendously different lifestyle.