He might have been introduced into the Dragon Ball franchise as a formidable fighter, but after the first arc with Emperor Pilaf, Yamcha was quickly made obsolete as the strength of new foes rose at a steep incline. This has continued to the present day where Yamcha has since become a full on joke, and often made the butt of many jokes from the other characters too as even they have realized just how little Yamcha has mattered to each of the major fights in the series. This is definitely the case with the manga's new Galactic Patrol Prisoner arc too.
Chapter 53 of the series has added yet another burn on top of the mountain of disses throughout the series already as while Earth's fighters are gathering the strongest warriors to fight for the Galactic Patrol, Yamcha is quickly ignored in the conversation and forgotten almost immediately.
With the fight against Planet Eater Moro and the escaped Galactic Patrol prisoners now coming its way to Earth, Bulma was tasked with gathering the Z Fighters at Dende's Lookout to prepare. They were going to be recruited to the patrol to officially join the fight, and Krillin reveals that while Gohan is on the way, he couldn't get in contact with Tien. But when he asks Bulma and Piccolo whether or not they should contact Yamcha, Jaco arrives and Bulma shifts the conversation.
From then on it's all-out action from a surprise attack by the prisoners, so it's clear that Yamcha will be missing out on the action this time around too. One of the more hilarious moments from the Tournament of Power arc was seeing just how Yamcha was excited about the prospect of getting recruited for the seventh universe team, and then was subsequently ignored while no one else even thought to bring him onto the team.
It seems it's the same case here as Yamcha just won't even be considered anymore. The fights have evolved far beyond the point where he could feasibly do anything about them, so it's almost as if he's fully become a non-combatant. There's no need to pretend that Yamcha being there will be worthwhile for series writer and illustrator Toyotaro, and now it's clear that the characters very much feel the same way.
Dragon Ball Super currently airs its English dub on Adult Swim during the Toonami programming block on Saturday evenings, and is also available to stream on Funimation and Amazon Video. The Japanese-language release of the series is complete, and available to stream on FunimationNOW and Crunchyroll. The manga has chapters that can currently be read for free thanks to Viz Media, and Dragon Ball Super's big movie, Dragon Ball Super: Broly, is now available on Blu-ray and DVD.