Stealth is broken

in two ways: an enemy who doesn't have a pink has no options for dealing with stealth, and there is no way of dealing with a pink in the middle of a teamfight (pinks and red trinket are hard counters).

These two facts have led to so many problems over the years, and yet Riot continues to ignore them, opting instead to constantly rebalance stealth champions. In short, because stealth basically doesn't exist in a high elo teamfight, any stealth champion has to be able to function in a teamfight while being revealed or they will never see challenger/LCS play. For example, here's a quote from Kha's reveal detailing his intended playstyle in teamfights:

Later in the match, Void Assault allows Kha’Zix to safely and aggressively navigate team fights. After leaping into combat, Kha’Zix can use his ultimate to evade attacks while he picks apart vulnerable members of the enemy team. Once he’s downed an opponent, activating Void Assault again can allow him to either safely withdraw or reinitiate on another target with Unseen Threat.

You may notice that this isn't at all what happens in high level play. What happens is he pokes with w, leaps in, kills something, then either leaps out or onto the next target. The ult is a nice ability that is useful sometimes but can't be relied on. Now let's look at Rengar, with a nice quote from Scarizard:

Yes, pink-wards do exist - but when he's running super fast and has a long-range gapcloser whether or not you can see him, the pink ward doesn't really do anything but give you a moment's warning before he just kind of executes his buttons on you and you live or die.

Again, he doesn't heavily rely on the stealth from his ultimate, and instead of the playstyle that was intended for him on release (can't reliably 100-0, has to keep fighting with AS boost or gtfo with ult) we have a champion that just picks a target to delete and either succeeds or gets bursted.

Another way to look at it is purely in terms of cost efficiency. Pinks and red trinket are designed to be cost-effective in games where there isn't even a single stealth champion. Riot would never dream of making an item with "activate to negate a single Akali shroud" yet that's exactly what a pink ward does. Their answer to the question "How should players counter stealth?" has always been "The same way they clear wards, duh" and they somehow don't see the problems that causes.

I have a couple ideas for fixing this, but keep in mind I'm not particularly attached to them. My main point is that there's a problem, not that I know exactly how to fix it.

• Pinks and red trinket no longer reveal champions
• Hard cc breaks stealth, increase # of champion abilities that reveal position but don't show the champ, like Noct Q and Kennen W (Eve Q and tether abilities are good candidates), OR
• Add items that soft-counter stealth (like a Rek'sai Q item, or one that points but doesn't reveal), OR
• Give everyone the Evelynn treatment, with varying ranges of detection (Vayne and Teemo could keep "true" stealth, while most others would have roughly melee range detection radius), OR
• Something else

tl;dr There is a lack of good counterplay for both stealth champions and the people they play against, and Riot is forced to balance these champions around the assumption that they won't be able to use their stealth in a teamfight, or they don't see competitive play.