For years I weightlifted without protein powder right after the gym. Usually my skeletal muscle is so pumped that my GI says, "No food please", for about an hour after the gym. The parasympathetic nervous system, which governs digestion, doesn't usually activate until you're at rest. It's the same reason why I only eat a snack before the gym and not a big meal. I listen to my body and eat when I'm hungry, which is usually not long after I've been at rest. The meal will be high protein, usually. Only in the past year have I started using protein powders because my protein-specific cravings have become so intense and I don't want to have to cook or ingest other macros when I just need a protein kick. Also sometimes I'm lazy and just don't feel like doing the proper meal prep every single time.
I can only handle whey protein isolate because the non-isolate has lactose and I'm lactose intolerant. Back when I was casein intolerant, I used a vegan protein powder that had pea and help protein combined. That was pretty good. Still didn't totally digest it though. My body loves animal protein so much. I've experimented with being vegetarian (8 years) and vegan (2 years) and my body just doesn't absorb veggie protein like it does dense animal protein. That's why I still use whey isolate. I was over the moon when my gut healed enough that I could start using whey again. Its effects on my health were profound, especially how it drives glutathione production.
The downside of using whey is that it drives IGF-1 and can be androgenic, which drives skin oil gland production. If you're already on TRT or other anabolics, whey might be stilting your hormone ratios enough to cause skin problems. You might need to use products on your back that target oily skin.