The Dachshund is popular today for several reasons. Firstly, they are small and a lot of new adopters during the coronavirus lockdown, who are inexperienced, want more manageable small dogs.
Secondly they are cute.
They were bred to burrow in badger dens to attack them. They were working dogs.
They are now companions but they have unnaturally short legs which is a disability.
Their mentality is the same as their bigger brethren. This pluckiness endears them to people.
Lastly these short-legged dogs were bred to tweak the “caring for baby” mentality of people. This helps to form a strong relationship.