Veto has high potential still given not many teams have adopted him or utilised him as well as they could.
The pros of Veto are that he is a solid counter to util-heavy teams and probably benefits from smaller maps as his TPs can be used for fast rotations or sneaky plays.His trip is a good piece of util as it offers so much value when it hits, but it is drawn back by the wind-up time, being easy to destroy if teams are silently clearing space and that it can bug out in certain locations leading to enemies not being seized. His ult is especially annoying to deal with as teams usually try to flush enemies with util, but this doesn't work on Veto in ult form. His interceptor is also great that you can set it down and trigger it from a global range.
The cons of Veto is that he is heavily defense-sided with difficulties on attack. Similar to Deadlock, his trips are easy to detect and/or bypass. He has TPs, but due to their wind-up time and audio cues, they are not the best entry utility. The interceptor is also weaker on attack as it can be shot out by the defense or waited out before a retake. Ultimately, he will benefit from highly mechanical aimers as seen when used by F0rsaken. He's not the type of sentinel player you want to always have lurking, but it can be great on occasion to create pressure by breaking utility.