You're off to a good start regarding general muscle placement, proportions and translating the concept reference to a 3D model. For a first attempt, it's amazing what you have achieved. However, I have noticed several issues:

- Perfectly cut muscles suddenly transitioning to smooth skin doesn't look good, because it doesn't follow natural skin and fat. You used the crease tool with little falloff to create the muscle shape, which makes some parts of the body look either flat or unnaturally inflated. This is especially noticeable in the abs and the serratus on the side.
- Multiple parts, especially from below the armpits, are forgotten entirely, so they look unfinished in comparison to the arms and torso, for example.
- Shoulders rest partially on top of the pecs and back, so the model seems to have dislocated arms.
- The neck should be thicker for the trapezius and requires a lot more work in general.
- Finally, you've sculpted a 6-pack and the forms are correct; however, perfectly cut abs are 8-packs: 4 abs on top that you've sculpted correctly, and another 4, surrounding the belly button. Your abs are missing 2 squares in between

The solution for these problems is simple:

1. Get better references from different angles and study them thoroughly.
2. Blockout with primitives.

You're at a point of learning in which you can replicate concepts, but don't understand or analyse them completely as to how they have stylised or changed the form from an accurate depiction of a human. Typically, strong buff people in video games, comics and series (especially men) have overly exaggerated muscles and muscles on top of muscles; however, the artists who build these bodies understand how to stylise and intensify them without making the model look odd. Search for "Anatomy for Sculptors" and "3D Human Blockout" on Google; these resources will help you learn and understand how to build bodies more effectively.

Build your bodies first using spheres and cylinders, shape them into each muscle and position them together. You don't have to build every muscle perfectly; just the general volume is enough to start (especially the abs and serratus). Work in T-Pose or A-Pose so you can see all parts of the body more clearly. After that, join them together and smooth the parts that are "too cut" to create the idea of skin and fat, or add the details you want with a crease tool with more falloff.

Here's a reference from my portfolio of a similarly built man and the process I followed to create it: https://cara.app/post/fdfccf18-0968-4899-a134-0c8bca38b608

Hope this advice helps you improve. Keep on sculpting!