Switchers in the 80s were only 80% efficient at best. The chips just weren't fast enough for much better.
Switching from maybe 70% efficient linear to 80% efficient switcher means only a 30% reduction to copper or transformers.
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Today, a switcher is maybe 95% to 99% efficient. So switching from 70% efficient linear to 97% efficient switcher is a 90% reduction in coils/heat sinks.
Switchers have much smaller transformers because the frequency is much higher, >20 kHz vs 60 Hz. (This is the same reason that avionics use 400 Hz power instead of 60 Hz.)
Switching from maybe 70% efficient linear to 80% efficient switcher means only a 30% reduction to copper or transformers.
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Today, a switcher is maybe 95% to 99% efficient. So switching from 70% efficient linear to 97% efficient switcher is a 90% reduction in coils/heat sinks.