They talk over the matter for many hours without arriving at any decision [closed]

Can you please explain why we used past tense instead perfect tense as it have duration of time.

Collins lists this usage of without:

without 4. (followed by a verbal noun or a noun phrase) not, while not, or after not:

she can sing for two minutes without drawing breath

There is no necessary indication of a durative process:

He left without saying goodbye.

though there is no contra-indication

It is impossible to really get to know San Francisco without living there for several years.

The time-setting is immaterial:

He had left / left / leaves / will leave without offering to help his wife with the housework.