If you are lifting your gate with your knee to get it to latch, you do not need a new gate. You almost certainly need one of these three.
The post has moved. Ground shifts. A post that is even slightly out of plumb throws the whole gate out, and it shows up as the far corner dragging in the dirt. Sometimes the post can be re-set, sometimes it needs concrete.
The gate has racked. A gate is a rectangle, and a rectangle with nothing bracing it wants to become a parallelogram. That is what the diagonal brace is for. If yours has no brace, or the brace has come loose, the gate sags at the latch corner. A new brace fitted the right way round — low at the hinge side, high at the latch side — pulls it square again.
The hardware is done. Hinges wear, screws pull out of soft wood, latches bend. Often the fix is longer screws into solid timber rather than new hinges at all.
Most dragging gates are a half-day at the outside, and you get back a gate you can open with one hand while carrying something in the other.
Send me a photo of the gate and the hinge side, and I can usually tell you which of the three it is before I get there.