That is something that has always warmed me to Bianca, that she not only pulls her own weight, money-wise, but she is always extremely classy and put-together without spending a fortune. Her ring not being the very most expensive jewel she could have and yet being tasteful and meaningful is her all over (from what I've seen!)
Even if Alice wasn't an abusive, soul-sucking nightmare, IG and her interests have never really been aligned anyway. She likes glamour, fashion and excitement and lots of expensive material things and expensive holidays (regardless of whether her travel companions will enjoy it - taking two small children to Harry's Bar in Venice for a ridiculous example), she likes being indoors, drinking heavily, dressing up for premiers and getting photographed, and is obsessed with social media. She really married the wrong person for her. But she's the type to have bankrupted anyone she'd married to be honest.
IG doesn't seem the slightest bit interested in being on social media beyond the bare minimum, loves being outdoors hiking, has stopped drinking, is happy to live a minimal life generally, splashing out on travel to spend time with friends and family - again, often outdoors, or visiting cultural places of interest rather than acquiring possessions (it always makes me laugh how many years he's worn the same jackets and sunglasses for instance). His faith and Welsh heritage has always been very important to him, whereas Alice doesn't have any interest in either thing.
Bianca's interests and values seem to slot in with his really well, which just makes any relationship easier. And she's engaged with the world - she wants to get out there and see things, learn new things, and not just because it's a sign of status. And again, she isn't a weight around his neck regarding money either, they both seem happy to live within their means and live fairly low-key lives with the odd luxury here and there. It must be such a relief not to have to watch someone spunk every penny he makes on a bunch of crap every time he had money in the bank. Now he just has to give her a regular, predictable amount each month. (Honestly, I'd bloody love to be divorced from IG - the life I'd lead on 10k a month for nothing!)