Per the original executive order from Trump the plan was to significantly increase the judges at the border to handle the claims, so the detention time was lowered. Under Obama the detention time often exceeded the 20 day limit, which is why he increased the funding by 3600%.
Mind you, most of these was 'At the Border' detention, because the people coming across had no where to go, no home, no transportation, nothing but what they had brought with them or that a Coyote had left them with. So if you gave them an ankle bracket and let them go....where would they go? Under Bush they had an in state detention building or 2, and some tents. It was very limited.
And an increase of border crossings is happening. Per the WaPo:
https://www.washingtonpost.com/world...=.901c20fb4afc
Triple from last year in April (from CNBC):
https://www.cnbc.com/2018/04/05/cros...-year-ago.html
But then, the number is historically down if you also read the news:
https://www.nytimes.com/2018/06/20/u...eclining-.html
From the same article:
So processing that many people is a significant amount of work - even if it has slowed.