Super slow progress and low strength for 4 years of training : 74kg(163lbs) 19M

I started lifting when I was 15 , was around 62kg but a couple inches shorter aswell so some weight gain was from height increase, and could bench around 35kg one rep max.

Fast forward 2 years, gained about 7 kg and only at a 55kg bench one rep max, despite focusing on chest and spamming side delts with volume.

Fast forward another 2 years , gained another 5 kg to be 74kg and at a 90kg bench, but when i compare to other people online, even nattys on youtube they all hit 100kg on bench 1 to 2 years in, 2 years at max, and it’s not like they are tall too like me, which gives me an advantage in strength.

I have been eating enough as consistently go up one rep every session, and have gained a decent amount of fat, albeit not much (~12% to ~15%)

I train to failure every session and every exercise, I see the people around me who are bigger and I go to failure more than them. I eat enough, and do enough volume to grow, and track literally ever lift I do, and get 8~9 hours of sleep daily.

Why on earth is my progress so slow, both muscle building and strength, considering i’m 19 and should have peak testosterone and muscle growth

Here is a training routine :

Push and biceps:

Incline db bench - 30kg for 11 x 2

Machine preacher curl - 80kg for 11 x 2

Cable side raise - 14kg for 16 x 2

Pec fly - 112kg for 10 x 2

Hammer curls - 16 kg to failure

Pull and triceps:

Weighted pull ups - 10kg for 9 x 2

Tricep push down cable - 40kg for 10 x 2

Tbar row wide grip - 40kg for 10 x 2

Tricep push downs with elbow movement for long head - 50kg for 8 x 2

Neutral grip pull-ups - 10reps x 2

Legs:

Will do some cycling, don’t really care about leg size always covering them up anyway

I go up reps pretty much every session and control the weight, how come with this progressive overload combined with enough food(gaining fat so definitely eating enough) , sleep and intensity I am still weaker than half the kids in my year at 15 who could bench 100kg

Thanks, first post on reddit