One of the key differences between rogue lites and rogue likes is meta progression. In most roguelites you're able to unlock things and get more powerful for future runs. In roguelikes you always have the same starting rng. I definitely agree with you that it's all up to the game to balance the progression through both unlocks and skill improvement so it's not entirely rng. But I also don't think many put much effort into "every run is solvable". Especially for roguelikes.

I'd say it's even worse for roguelites. They tend to balanced assuming the player has done some or most of the meta-progression. Sometimes to the point where it feels the game forces you to lose to experience more of it. (I really liked inscryption up until it forced me to fail 2-3 times because I progressed too much)

With roguelikes at least you are at the intended power level every time, even if some of these games are too RNG reliant.

With real roguelikes (aka games on a grid with turn-based combat), I believe they're not designed to be fair at all. There's so much rng involved, so you will get unexpected and unfair deaths and lots of them.

Roguelike community has a saying - "losing is fun". And while I only played a few traditional rl games and finished none of them, I had great experience while constantly "losing" only a few hours into the run.

In most roguelites I play, losing isn't fun - it's frustrating. There is often very little variety in earlier stages of the game, so if you're bad (and I am) you're stuck replaying the same section for hours, only to get good RNG, go 1 level farther and immediately die to some new mechanic or difficulty spike.

One exception is The Binding Of Isaac, this is probably the best roguelite game I've ever played and nothing comes even close.

There is fair and then there is "fair". I do think most rougelikes spend at least some time on making sure the the default path is usually workable. I think roguelites fall into the trap of relying on meta-progression to push in-game progression too much. Some of the card roguelites I play feel impossible to "win" without meta progression. And in some it feels like they mostly expand complexity. It's a difficult thing to balance. I'm mostly okay with the difficulty spikes because they usually accompany power spikes that you can get with the right choices and rng. I really like the "breaking the game" aspect of roguelites like Balatro. Getting mathematical notation for high scores hits different, even though it's not necessary for beating the normal levels.