I looked for an answer for my Kosovo question and it's probably because of: "The Kosovo Digital Economy Project (KODE) was launched in 2018 with the goal of ensuring that all Kosovars have equal access to digital opportunities."
Like most things, it's difficult to shake it all out to one variable.
An obvious example being Italy, whos demographics skew very old. Poverty or not, you'll find many 90 year olds who've never used the internet (and if they did, they maybe didn't even realize that it was)
Bayern is also a good example counter example against the poverty argument. Very wealthy region, but in 2021 they apparently had lower internet adoption than most other west-german regions. Saarland could be seen as an example of the poverty argument, but also of the age argument: it's young people that move away.
Galicia in Spain is also wealthier than average in Spain iirc, but the map also shows them as having lower internet adoption than the rest of Spain.