Might've been "unprecedented" at some point... MC34063 is still disturbingly popular, and was probably the only thing that did an ampere (by itself) for a long time? No idea.
Datasheets rarely carry dates, so it's hard to say what the timeline is when that's what you're looking at most of the day...

At any rate, 2-3A internal switch (regulator) devices are pretty common nowadays, even in very small (SOT-23-6, DFN/QFN..) sizes.
I suspect LT preferred BJTs partly because of their captive foundry capability, and partly for performance, at least at low supply voltages (good luck making a 40V MOS switch that runs on 2 or 3V).
Vce(sat) isn't a constant, it's largely resistive too. In fact there are low-Vce(sat) and audio muting type BJTs with specs any FET could only dream about. A jellybean that's 2A, 80V, 20mohm and only 50pF? You bet!

Tim