That's the most upsetting thing about this situation, in my opinion. Police in DC haven't had issues deploying such tactics in the past. Why was this different?

The instances you are referring to from the past were from police units that were fully prepared for riot combat. From what they were wearing and what weapons they were carrrying. They were also fully briefed on being placed into a riot situation. For the Capitol Police, it was just another Wednesday. There was no advanced prep for them to outfitted with riot gear/weapons. This is why it is so important to investigate the decision making process by leadership on why it was not something more than just another Wednesday.

Plenty of gas was used, and so were other less lethal weapons.

https://www.youtube.com/watch?v=6PCHra6JuuQ&t=3s

Gas, flashbangs, and guns were used at the Capital on the 6th.

1:100 doesn’t make escalation a wise decision