12v Philosophizing: modular/component vs all-in-one system

Thinking through the benefits and trade offs of the different options for 12v off-grid power for campers, vans, overlanding, cabins etc. Which one has worked best for you and why? I have slowly built up 2 decently capable component systems in my van and trailer, but these all-in-one power stations are amazingly simple. Different budgets, goals and needs will lead each person to their own system!