There is absolutely no doubt that Assad has been brutal, but where do you get the idea that the people of Syria - meaning all the people, want to get rid of him?
It is largely our fault, because as with Egypt, once the Arab Spring started, there were demonstrations in Syria, and the US, UK and France saw an opportunity to rid themselves of Assad. So, that was when we started funding, training and arming so called "Syrian rebels" - mostly radical Islamists from previously proscribed terrorist organisations including ISIL and Al Qaeda, in order to overthrow the Syrian regime.
The rise of ISIL started after the invasion of Iraq, when Sunni Muslims found that they no longer had the backing of their dictator - Saddam Hussein, so organised themselves into yet another terrorist organisation.
So yes, much of this would not have happened, if we had not invaded Iraq, and not tried to plunge Syria into chaos.