sen viper ults

can someone explain why they always use it at the start of the round? it's so easy to play around no? geng has just been hitting the other site and going around it.

so basically they use it to funnel people unto the other site, what geng is doing is putting heavy pressure into the other site to clear out the site the viper ult is on and hitting the other choke.

bc viper ult is pretty bad on defense so most teams use it to control short or long. bascially so they know u cant come that way making bind a 3 lane site instead of 4