Nationalizing oil and distributing the funds to a variety of people-focused projects was the crown jewel, yes. Not just social welfare, it supported (supports, technically) the neighborhood/regional councils, the indigenous-focused anti-poveety projects, and, relevant here, economic diversification efforts, particularly food sovereignty projects. The latter was interfered with by sanctions, as substituting importa for an entire extraction economy in mere years is not possible.

Venezuela has substantial socialist formations including those who were in the orbit of Chavez. It also has and had plenty of opportunists, both in the "socialist in name only" sense and in the "I am literally a capitalist making deals at your expense" sense. As everywhere, the revolution leaves you with, more or less, the population you went into the revolution with, and Venezuela had a reformist "revolution" largely at the ballot box.

People here do not say that socialism is when there is some nationalization. But nationalization is a socialist policy, it is something you, a socialist, focus on using the state to do, as it expropriates the means of production and makes it something that can be leveraged by the political organs of the mass oppressed classes.