Assad had majority approval prior to the war [1] (can't find any more recent adversarial polls, which may be telling) and his family has been in power for decades. The comparison is inappropriate.

It's more akin to saying that states adversarial to the US won after the CIA overthrew a popular secular democracy in Iran, and installed a extremely unpopular puppet monarchy that was obseqious to the US.

In general maintaining power without relatively widespread support is quite difficult - probably even more so in the digital era which makes conspiracies so much easier to organise.

[1] - https://www.theguardian.com/commentisfree/2012/jan/17/syrian...