“I don’t think it’s possible to get rid of Assad now that Russia got involved.”
It does look like the military attempt to remove Assad has failed, but they have long been working on a settlement deal diplomatically, that would have Assad take his retirement, as a part of a whole settlement package. The deal is not finalized for Syria’s future.
Right now, it seems (much) less likely that Assad would leave than when his regime was on the ropes, but it looks like we will keep a wedge in there with our presence, building up the Kurds/SDF, throttling redevelopment funds and other pressures. Circumstances will change again.
The Ba’ath Party needs to re-brand themselves, and drop their Nazi racial ideology (Arab Nationalism) to join the modern world. The same guys can sit at the same desks, like with former communist regimes, but Assad (the Assad family) leaving is the major symbolic change to indicate a real break with the past. Also, no freely elected Government can securely change power there, while the hereditary dictator remains looming.