Here's where I think your argument ultimately fails to see the full picture, and something @Roux also hit on. CSGO TTT is fundamentally different than Gmod and I have a real problem when changes are based in any way on "how it should be" because that's what it was like in Gmod. While, like in anything in life, it is important to at least acknowledge and make certain conclusions based on the successes and failures of Gmod TTT, you have to understand that at this point we've (other communities included) already molded the server from what works long ago and made our own variation, which for obvious reasons is highly influenced by the game the players have chosen to play. I'd be much more compelled if you had made the claim that kevlar will improve the overall balance in the gamemode, it makes it too competitve/not fun enough, and/or that it's simply too easy as a T rather than trying to say we should mimic another game that is vastly different from the one you're playing. To that point however, I would still disagree for a variety of reasons. Firstly, I think it's worth considering the fact TTT may already be quite balanced as is. When you say
you vastly overstate the ability of a traitor in a situation such as this. Out of nature of the game mode, innos aren't just mindless apes who pay no attention what's going on. They're naturally vigilant given the entire point of the gamemode is either to kill everyone or survive the ensuing T's who you KNOW will try to kill you. A traitor should, and IS, able to kill a couple innos with a decent chance of living through it due to the ratio of T's to innos & detectives. If a t really is able to just walk into a room and demolish 4+ people without taking a bullet, it's a lot more reasonable to scrap it down to skill imo. In that situation, either the traitor is far superior to the average player or the innos are far worse than the average player, essentially two opposing extremes. Since they're the extremes, they're also therefore the minority and justifying major balance changes based on a few rather than the rest of a whole isn't very appealing. Nextly, I believe wholeheartedly traitors should be able to 1 tap with no problem. What happens when a bunch of people group up or follow a detective and you aren't that extreme variation of the player mentioned above? Three-four different things are the likely choices,
1) You decide to buy something in the T menu that would make your life easier like a C4, Jihad, mine, etc. which promotes diversity and unique gameplay opportunities (obviously a desired outcome)
2) You take your time and strategically remove people 1 by 1 with one taps, maneuvering your away around as to avoid getting targeted by 30 million innos at once (maybe buy an m4a1-s to make that easier?) or
3) You coordinate an effort with your t buddies and start spraying or tapping at the same time and cause mass confusion
If you were to add kevlar, you essentially limit the possibility of certain choices and reduce the options available to a traitor outside being forced to buy an item (which you may not have the credits for). Lastly, I would like to argue against the idea that kevlar (or a lack thereof) is the driving force of over-competitiveness, despite this argument being the most appealing imo. The reason I believe this to be false is that before the karma update, I think generally the game mode was FAR less rambo-esque and fuctioned like less of a DM server. During that time period we didn't have armor though, so I fail to see the correlation. I think you would be more effective in discussing changes to the karma system and providing less incentive to kill as many people as possible if you think that would improve the experience. But EVEN in that claim I fail to see the validity given the popularity following the karma update. While it is a diffent TTT then the one known prior, we should be more focused on what the players want as opposed to what the ideal gamemode of a single person would look like.