Did the gas company measure the gas pressure?
Some gas control valves can be adjusted for pressure.
Thermocouple test from Rheem manual: “With the pilot flame lit, turn OFF the gas supply and start to count seconds (one-one thousand, two-one thousand). Count for a full twenty (20) seconds. The pilot flame should be out. Listen carefully for a small clicking noise at the gas inlet side of the valve. If you count for the full twenty (20) seconds and do not hear a click then the thermocouple is fine. If you hear a click within the twenty (20) seconds then the thermocouple and or gas valve is bad. Replace both the thermocouple and gas valve.”
Is the burner clean, or does it have black soot that indicate insufficient air flow or slow venting or clogged burner orifice? Clean combustion parts with water and wire brush.
The pilot orifice might be dirty. Clean with carburetor cleaner. Clean pilot tube.
Make sure thermocouple is embedded in pilot flame and that pilot flame is strong and clear blue.
Is the burner flame clear blue and strong. Or is the flame yellow. Yellow indicates low gas pressure or dirty combustion parts. And or insufficient air flow. And/or bad gas control valve.
Inspect and clean flue way.
Let the burner operate until it is hot. At the vent hood on top of tank. Light a match and hold match just outside the vent hood where air is pulled in. Blow out match and see if smoke is sucked into the vent. It should draft in and upward immediately if vent is good.
Look at top of water heater for signs of sooting that indicate another gas appliance might be pushing vent gas back down water heater vent and blowing out pilot.
Close all doors and windows. Turn on all the exhaust fans and vent fans in house. Water heater burner is off. Light a match at vent hood and put match under hood and blow out match. Does smoke draft immediately upwards? Of does smoke draft downwards? Downdraft would indicate negative pressure is causing pilot to blow out.