Layering products-does it actually help?

I would love for someone to correct me if I’m wrong or at least guide me in a particular direction.

and I also know skincare is very specific to each person. but when I see people on social media layering product after product on their face, is this actually helpful? how can products penetrate the skin or be effective if you’re immediately putting on 5 products, one after the other?

because some of them do seem to have beautiful skin and as someone in their late 20s, I’m starting to get more serious about barrier repair as well as incorporating actives so I can brighten and tighten. but I’m definitely struggling with wanting to buy a lot of products.. any insight would be helpful