Top 3 network shows that shouldn't have been network shows
If a show was on one of the major networks, historically speaking, they were meant to entertain an audience over the course of a year. This meant a season started in the Fall, ended in the Spring, and the final episode count would be at least 20 or more. Shows made for streaming have the luxury of not being tied to that standard. They can tell their story and move on. While this means a lack of filler, it also means an easier binge with the story not being dragged out to an unnecessary point. These 3 shows definitely would have benefited from this format.
Once upon a time
This is probably the show that needed to be a non network show the most. Not just episode count but for budget and time. The most powerful characters were constantly nerfed for the sake of plot. Oh no! The Evil Queen was thrown across the room. The villain got what they wanted. I think splitting up the seasons between two arcs really helped but if they had the time & budget and didn't have to prolong a plot, powerful beings like Rumpelstiltskin would win every time.
Supernatural
Filler is what makes Supernatural fun. However, I also think they have to make the boys extra stupid so they can keep losing or stay one step behind so they can prolong the plot and have their big moment in the season finale. Characters like Cas are also hella nerfed - like when a video game boss becomes a party member. While the episode count makes this a hard binge for newcomers, the filler makes it easy for fans. But if it were to work, maybe divide up the plot like Once Upon a Time did? As for it's benefits were it to be made for streaming? Graphics. I think with a better budget, the effects would've helped make the show scarier. I personally only found maybe a dozen episodes actually scary despite this being a horror show about the SUPERNATURAL. I also wonder if there was a specific rating rule from the network that affected this as well.
Agents of Shield
Shorter seasons to minimize a prolonged plot. Better budget and more time for better graphics. Sure, this show could've benefited from this. Specifically in season 1 as the first season used filler at the start as it waited to align with the Winter Soldier movie. But for Agents of Shield specifically, it's sad to see current Disney+ shows get so much praise and become important to the canon, while Shield was just thrown aside despite all the good work it did. Wrong place at the wrong time, yet it was still right where it needed to be.