Assad has been able to achieve the normalization of chemical warfare, but also indiscriminate shelling, mass executions, intentionally targeting civilians and much more, still gets away with everything thanks to his Russian master and accomplice Putin.
A big thanks goes out to Obama too (the worst US president in history), who claims his best decision for Syria was to not carry out bombing Assad, even though Assad had crossed his red line on chemical weapons. This made them more bold and free to carry out war crimes with impunity.