MSC’s aren’t offered as much anymore because they had the same problem as PhDs (it could take 4 years to finish one) without the prestige of a PhD at the end. They don’t even guarantee much of a jump start on a PhD. These programs have mostly been replaced by professional non-thesis or thesis-light options, along with “5th year” programs at universities that tack on a few courses and a straightforward thesis to an undergrad program (MIT is famous for these, many universities have copied that).

European universities often have the latter 5th year programs as well where they are considered even more crucial because many of them have only 3 year undergraduates.