The original SARS didn't have the qualities needed to be a world-wide pandemic, though, and one of the big obstacles to that was that it was just too deadly. Not only do people who are so sick they have to be hospitalized not go out and socialize and spread the disease, all the hospitalizations and deaths gives a whole bunch of really obvious starting points for contact tracers - instead of only knowing about a tiny fraction of cases, most of them are highly visible and those people's contacts can be tracked down and isolated before they become infectious.
Also, a lot of governments did take suitable precautions in case Covid was more like the original SARS early on and just got flak for it. This was particularly visible here in the UK, where Public Health England and the government had already planned for another SARS or MERS-like virus and introduced really aggressive testing and contact tracing early on in case this was it. They just got attacked in the press for not continuing that once it became clear this wasn't like SARS and it wouldn't work - and then once they gave in and reintroduced testing and contact tracing as a measure, they were attacked again because (predicatably) it wasn't that effective and the media fuelled endless badly-informed conspiracy theories about the testing and contact tracing program only existing to funnel money to their pals.