In field hockey, in Australia's domestic competition, getting rid of the offside rule started by first getting rid of it applying in the "middle" 50 yards of the ground as a trial, this matched/followed the changes at elite level. So offside only applied in the two 25 yard "ends" of the field. It was trialled as a complete "no offside" at the elite level during particular competitions, and the various nations agreed that at "international" level there would be no offence rule. From that, individual countries made their own choices for domestic competitions, but it was clear that at "international" level the offside rule was gone, so domestic competitions followed that trend.
I think it has slightly increased the number of goals scored from "field" play ( as opposed to goals scored from penalty short corners & penalty strokes). It didn't lead to a dramatic increase in the number of goals scored. Nor did it lead to scrums of attacking players hanging around the goals of goalkeeper.
I think if anything it opened up the midfield play. In that the fullbacks could not both push up to the centre when their team had possession of the ball in the attacking half of the field.
The value of the beautifully timed, positioned and paced through ball pass is not diminished, if anything it's even more important.. Because a team tends to have one player "up high", but watched/covered by a defender, then holding possession as a team attacks through the midfield and then co~ordinating the right pass to that high player is super important, and that player needs excellent skills and judgement.. Does that player go for some quick movement and a shot at a goal, do they hold possession ( even moving away from the goals and taking defenders away from the goals ) and then pass to a team member who has run into an attacking position in the circle for that player to try a shot at a goal, or does the high player use their skills to draw a penalty corner from an infringement/mistake with a tackle by a defender.