He’s lifting. He’s already ahead of most guys. I know guys in pretty good shape who work in that rep range at that weight. Some of them are still learning to bench, some are thinner guys with smaller frames but muscular and 135 is good for there they are. Some guys can just flat out lift a lot more because they’re more advanced and/or have bigger frames and can naturally blow last 135 faster because of how big they are. There are plenty of guys who just don’t need to go all that heavy to get great results because they are still working their way up or are just not big guys. If he wants to lift heavier, stick with it. Use progressive overload. Add five pounds every week or two. Don’t rush, the results will come. Patience and a programmed game plan to progressively overload will work with consistent work and adequate protein. I am 5-10, 160lbs, good body fat numbers and look stronger than I am because my muscle is visible. I need 160 grams of protein a day or i won’t grow. Whenever I slack off on the protein I take a step back. With my bone structure and wrist circumference and skeletal width and length I will never mechanically be able to bench 300, not even close. Even if I hit my genetic ceiling. For some guys, it’s attainable. Every body is different. Have him set goals and work towards them and as long as he is advancing towards those goals, be patient and keep going. Once the results stop improving, then adjust. He’s doing fine.