Ever since the closed beta when Riot Games introduced Viper as a playable character in VALORANT, the whole community unanimously agreed that she is the least viable agent in the game.
After the official launch of the game on June 2nd, Viper has the lowest pick rate among all other agents. It was super obvious that Viper was so underpowered as she was not chosen even once in VALORANT’s twitch rival tournaments.
The main problem lies with her utilities as they are not that useful. Consequently, her pick rate in unrated matchmaking is very low. Although Riot has just started to balance each individual agent one after another.
Recently they started with nerfing Sage as she was the most popular agent in the game. Her pick rate in high tier competition was near 100%. Therefore it was obvious to Riot that she needed some kind of nerf.
Viper is getting a buff confirmed by a dev
In the upcoming patch, Viper is supposed to get huge changes to her utilities that will make her more prominent in the game. One of her abilities called snake bit is confirmed to receive some kind of change in the next patch.
Furthermore, her toxic wall/screen will also get a buff as she will be able to place her toxic wall through walls. Her toxic screen ability will be able to pierce through the entire map. As a result, she will have a ton of new wall placement opportunities.
With the upcoming Viper buff, Riot will ease themselves into balancing every other agent in the game. As it stands right now some agents are just inherently better than others. Although soon that might change for the better with each individual update.