53M, 172cm, 65kg, can't get past 80kg X 6 reps of bench press. What to do?

I see a lot of posts on hypertrophy suggesting adding 1 rep per week. That seems impossible to me. Can't even add 1 rep per month. What am I missing? I am just trying this out with bench press for now.

I train chest twice a week. For my first exercise, I would do 5 sets of incline - 1) 60kg X 10 (usually not maxing out), 2) 80kg X 6 (maxed out), 3) 80kg X 6 (maxed out), 4) 70kg X 7 (maxed out), 5) 70kg X 7 (maxed out). I just can't get past 6 reps for 80kg. I usually get into this after a 10 minute warm up run on the treadmill.

Any other suggestions welcome...