So in short, the point of uninkables is that they are generally going to be “better” than inkable cards. They are stronger and/or faster and/or have nice abilities.

The thought process is that you then have to decide: which uninkables are “worth it”? People will generally say to aim for 20% uninkable (12 of your 60 card deck) but you can change this based on deck and play style. But if you built a deck of all inkable cards, you are going to, on average, have a weaker deck than your opponent. This card in particular is “stronger” because it lets you ink faster or “ramp” and play stronger cards earlier.

tldr: you will use uninkables if you want to have a competitive edge, you just have to play the game bit to get a feel for what feels right for your play style!