Free always comes with some restrictions. In BDO, free means it takes longer to level up, and without a pet, it is more challenging. The developers (who are now the publishers) want to funnel people into the store to buy things to make gameplay less burdensome.
"Hard times create strong men. Strong men create good times. Good times create weak men. And, weak men create hard times." - Those Who Remain by G. Michael Hopf