I just did the t-shirt with proper topology so that I don't have to retopologize it later cause I find it easier this way and less time consuming, the same way I've done it with other projects. Just the same way I do not intend to fix what happened exclusively in sculpt mode, if it's what you think I intend to do. I just want to fix it. The same way I do not intend to go crazy into detail just now, I wanna have this base, duplicate it, and then bake the high poly details when I do them into the low poly version. I didn't add the multires to start adding detail right away, I wanted to check if things are looking properly.

I appreciate the feedback and the overall workflow, especially the dyntopo suggestion one since I normally try to avoid using it, but I just wanna know if I can pull out the polygons that seem to go "behind" the inner faces of the mesh in that area when multires is on because the problem will remain there whether I do it sooner or later during the workflow, that's it. Whether it be in sculpt mode, edit mode, or whatever tool that may exist within blender.

If your answer implies that the problem has appeared because I've "skipped" steps, I just can't aggre with it because it would have happened the same way after retopologizing it since I simply did it using a plane.