It’s extremely difficult to use deadly tactics when the officers can be arrested, tried, convicted, and imprisoned for doing their duty. Departments can also be sued for huge sums of money depleting their already about to be cut budgets. The city also has the ultimate authority to dictate the tactics and equipment allowed, and Seattle has purposefully hamstrung the department which is the reason the department is using these soft handed tactics.
I work with quite a few police departments in three states in the SW and I can tell you that most would be more than happy to crack some criminal skulls, but this soft hands off approach is widespread across the country due to how the media unfairly reports arrests and how litigious our society is.
The same reasons also apply to Federal police as well.
Someone should develop a dye they can spray over the rioters. The dye should have a incident-specific identifiable component. Then they could pick people up and prosecute them at their leisure over time.