In the past 5 months I've gotten my bench from 115 to 127.5 (paused) and climbing, after being stalled for quite a while, bodyweight unchanged. The difference: benching 3 times a week and lots of volume, whereas before it was super high intensity 1 day a week and speed work 1 day a week.
This year, I had success with both higher intensity + lots of accessory work (RTS) and with lower intensity and very little accessory work (Sheiko #37) - but in both instances, I think the key was frequency and incorporating paused work off the chest. Each 4-6 weeks, I've only picked up 2.5kg or so but I've been much more consistent than in the past, so over time it has just added up.