Riot is currently pushing some binary champions to have a little more skill expression, basically trying to raise their skill ceiling so that players can feel more rewarded for putting more time into them. The addition of a small window on Garen's W where he is less susceptible to cc was a good change, same with the Volibear knockback.
I'm sure Riot is working on similar QoL changes for many older champions if they can figure out a direction that makes sense. This still doesn't mean they'll become viable at the pro level, and I still assert they're not meant to be.
Building a system of hard-counters unnecessarily restricts the design space Riot has for new champions, which is what it seems you are suggesting. If you have to make sure every champion is viable, and the lever you use is 'hard-counters' you are basically asking for a redesign of the whole game. Otherwise if certain champs only have a single hard-counter, and then are banned away you have a stale meta where these unstoppable beginner-tier champs are dominant.
Differences in kit will only get you so far, you have to look holistically at the types of abilities present throughout the game and their natural play patterns rather than just looking at a kit and trying to make it powerful enough to see pro-play.
I would recommend going through the old Quick Gameplay Thoughts in Dev corner, as well as the Red Tracker, and other relevant posts made my Meddler and the balance team. It should give you some insight into the types of things that go into champ design, balance, and why some champs are in the state they're in. They will often talk about toxic play patterns, and they released a video about the way the assess 'off-meta' picks and their contribution to game health. These should all give you a better idea of how champs are meant to interact, why some champs are more beginner friendly, and possibly you'll come to the same conclusion that they have. They also will sometimes deep dive on the intentions behind some champions' kits and hits and misses and how they decide to change things.
At the very least it seems you need a wider base of knowledge about the reasons champs are designed the way they are (though sometimes the answer is just "They're old" and Riot has learned a lot since the game was released) and those resources should help you paint a clearer picture than just X is a counter to A, B, C.