Is it the time or temp that gets you your desired doness for a steak
Enough time makes sure the meat is at the same temperature all the way through and for tougher cuts extended time makes your meat tender.
Both… Temp makes meat tender. Tougher meat needs more time. Thicker meat also needs more time. Time is less important. Doing a good steak 2 or 2.5 hours is no problem. Doing a tough peace shorter makes it less desirable.
Temperature for done-ness. Time for texture.
Rule of thumb says that it takes about 30 mins per half inch of thickness for warmth from the water bath to penetrate meat. So to get a 2" thick piece of steak up to temperature equilibrium (centre same temperature as water bath) will take approximately 2 hours.
Steak is usually cut from naturally tender muscles, so with most steak this is all you will need to do before drying it off and searing it in a hot pan.