Why hasn't Steele been arrested yet, then?

From Zerohedge article

"But most of the important claims in the dossier — which was written by Mr. Danchenko’s employer, Christopher Steele, a former British intelligence agent — have not been proven, and some have been refuted. F.B.I. agents interviewed Mr. Danchenko in 2017 when they were seeking to run down the claims in the dossier." -NYT

Danchenko was just a messenger. Steele is the main culprit re: Russia narrative. Enough has been "refuted" to warrant an arrest here. Why go thru the trouble to arrest Danchenko buy let Steele remain free right now? Does Durham think this will spook that spooks and lead him to the upper levels? It could be argued that with Sussman's arrest, and now Danchenko's, that there would be enough to go after Steele, Podesta, Humin, etc. Maybe even [HRC] herself.

Why hasn't Steele been arrested yet, then?