I think Khan's ultimate need some rework or nerfs. Right now it's just too good. On low elos drogoz' or bk's ultis are really powerful because people don't know what to do, they don't know what ultis do etc, so they don't position themselves properly etc in respose to those. On higher levels though they become one of the most risky ultis to use. When experienced people hear drogoz is ultiing they immediately look after him, and focus the fire. Sha lin can use plantd, jenos can fire his ulti, you can use bk's or skye's ulti too. Very often drogoz will flee or die immediately after ultiing. The same goes for bk. The higher the level the harder those ultis are to use. Your skill at using ultis may rise but players awareness will rise faster.
But Khan? In his case it's the opposite. A bad Khan will ulti while low HP, wrong target or just in wrong place. But there is absolutely no counter against Khan that knows how to use his ult and it's easy to know this. The range is so huge you can easily grab people from safe position and then you or your team will finish them. The only way is to kill Khan but thanks to his range he can easily hide behind the cover most of the times plus he is 4k HP so not an easy target to burst down. And most likely it's going to be a trade at best because his victim will likely die anyway.
I think Khan's ultimate should be much more risky to use. One way to do this is to simply reduce the range drastically so you have to really expose yourself.
Another way I can think of is to let the victim shoot or maybe even use abilities except the movement ones? Basicall jenos grip with criple and the ability to move and push your target. This will add a lot of risk since you won't be able to use your ulti as finishing move while you're low hp plus a poorly executed ulti could potentially cause harm to your team. Also this adds obvious ways to counter , for example as a Skye you can just drop your bomb forcing Khan to immediatelly release you and escape.
There is a lot of adjustments we can do here. Maybe don't allow for use of utlimates or maybe allow players to use them only after like a second of being gripped? Maybe do both to some extent, reduce range and let victims shoot?
Right now it's risk free, low skill floor, highest reward ulti and it's wrong.