@GreatSaiyaman123
That's a surface level way of looking at it. A technique can be improved, but the characteristics of the technique should be considered when judging
how it's improved. Attacks that impact the user's life are generally avoided by fighters; that's why they're often portrayed as desperation moves, like we saw with Chiaotzu's self destruct and Majin Vegeta's explosion. Tien is a rare case of someone trying to further hone something that carries such a risk. When the Shin Kikoho was introduced, the only thing noteworthy about it was the immense pushing force that it produced. It did no damage to Cell, though it was useful as an obstruction tactic, so it's an improvement over the original nonetheless.
One can come to this conclusion from reading the manga. And on top of that, this aligns perfectly with how the Shin version is described in Daizenshuu 4.
"A technique that increases the force of the Kikoho. An attack that becomes possible when one has improved their abilities through intense training. Tenshinhan fired this technique to stop Cell from moving when Cell was trying to absorb No. 18, but he used up all of his power and collapsed."
and the guidebooks said but Tien was clearly a force. Not that he wouldn't lose against Semi Cell in a fight still but he was clearly super saiyan level considering he didn't die instantly from Buu.
