Can someone explain gear drops?

Been farming all day I am lvl 73 and everything dropping is garbage and not even upgrades anymore.

How do you get gear to drop that is higher gear score and level appropriate?

like why am I pushing tier 23 night mare dungeons for no gear return to be able to move up???

My level 67 gear is still what I am wearing.

This is what I was afraid of loot drops being as bad as all other diablo games.

Am I missing something? world t4, pushing 23 -24 nightmare. can’t go any higher because no upgrades are dropping!!!
I have so much crafting stuff I dont really need since nothing is being used!!!

Example I have a lvl 67 hammer 2243 dps a second
new drop hammer lvl 73 1527 dps a second what a PoS

Generally, in diablo games, ‘good’ gear wont drop till you are in hell+

thats not even a thing

lets get more world tiers then cause I will lose interest fast at this rate