Both have pros and cons. Capital intensive businesses, once running, have their own barriers to entry (moats) "literally" built in: all those capital requirements help keep new entrants away. Capital-light business (and I am not sure the infrastructure investments to run a cloud service platform are so small), need to build this moat either by having access to consumer (data, network effects) and/or by keeping ahead of competition with constant innovation.
There are oil refineries that are decades old and still generate plenty of cash for their owners (granted, they need maintenance investments, but the bulk of the investment is certainly at the beginning), the same goes for cargo ships etc... While FB and GOOG need to come up with a new product or service every 6 months to keep those customers (see SNAP and their allegedly better fit with younger users). And MSFT wasn't in a very healthy situation just a few years ago. I have of course generalised and things are never clear-cut: servicing the high debt used to finance initial capital is also quite risky.
