Well, I think its good to realise that its different amounts for different people. There are 40 year olds that can’t bench 100 pounds, which is absolutely fine, because weight lifting is about keeping your body in healthy condition and being safe about it. So for some people it may only be safe with 70 pounds and doing more reps.
The most important thing is to do it safely to make progress. Excessive weight lifting can stunt bone growth, however with decent weight amounts it increases bone strength, ligament, and tendon strength.
Hopefully you aren’t just doing max lifts, which is more strenuous on your body. Doing 4-5 sets of 15(warm up),12,10,8,6 reps while increasing weight of each set seems good for me.