I’ve ridden all over the northern hemisphere. The UK does have some absolutely excellent, with Scotland standing out for me. Similarly I rode near Big Sur in California which was great, I always love riding in Spain with its abundance of singletrack and massive open spaces, the riding in northern Italy is wonderful and varied, the riding in France is awesome but crowded, the West Indies has some real rain forest gems and as previously mentioned, Croatia has some incredible riding where bumping into another rider is a reason to stop and chat because it’s so rare.
On the flipside, I love Scotland but hate midges. I love where I live now, but it does get awfully messy in the winter, and is crowded on the trails (although not as crowded as Brackley or the North Downs).
Is there anywhere better than the UK? Probably, but it really does depend on what you want.
Personally I do intend to move somewhere warmer at the end of the day, but it will be near to good riding.