There's a couple of issues with the ACB thing IMO:
1) quality of coverage - I too have been impressed by the quality of coverage. Its better than whatever company broadcasts BD matches (which has improved slightly once they got rid of that awful red and yellow color scheme). But the ACB weren't rejecting it on a quality basis. It wasn't a 4K vs standard def issue.
2) TV broadcast vs internet stream - As viewers we're only concerned with the accessability and the quality of the picture. But without a TV broadcast, there are limitations for the 3rd umpire in adjudicating certain close calls. I think there was a situation in the 2nd ODI where a Zimbabwe boundary was only given 2 runs because the 3rd umpire wasn't able to review whether the fielder had made a clean stop at the ropes or not. Its one thing if the 3rd umpire still can't determine it, or even makes a mistaken call (eg that stumping in the Sri Lanka Test in 2017). But not having the full tools at his disposal is really not inspiring.
3) And here it looks like like the broadcast, in whatever capacity, has been unreliable. The bottom line is its difficult for any board to have full faith in anything the ZC says. Even if ZC agrees to tour Afghanistan for example...at the last minute players will go on strike or ZC might claim that they can't afford the flight out unless the ACB pays for it (in addition to hosting expenses) at which point a cancelled tour is a lost opportunity for Afghanistan who could have hosted an Ireland or a Sri Lanka instead.
