Why I don't like Akali and Evelynn as Assassins

I have to say I love playing Assassins, with the exception that I also prefer AoE damage. My whole mindset works as if I am about to assassinate enemies, so I can tell how I personally feel from my perspective.

Having played Akali, I don't feel good playing her. She is an Assassin whose kit is mainly made for single-target killing, while having to continuously deal damage for a few seconds with the same combo. Throw Q, move back, go back in, land BA, throw another Q, throw W, get out of the circle, move in, land BA. This ability is made to be spammy and that's all about it. It doesn't contribute to the Assassin playstyle. Despite her high Energy cost on her Q (which gets partly refunded in a lot of ways, giving even more casts before running out of Energy), she is made to spam it every 1.5 seconds precisely, since it is supposed to be landed right as soon as you proc your passive on your enemy. It doesn't even have a cooldown for that purpose.

Her ultimate is fine in terms of skirmishing. It used to be single-target, now is a really good ability. It feels cool, if anything. But just an ultimate doesn't make a champion be enjoyable altogether.

Evelynn just has the same issue, but this time even worse. Her Q is a skillshot at first, which is reasonable. The next part makes me question why it even exists. The damage the spikes do is insignificant and the way they work is simply "spam Q, do 300 damage" in late game. Extending the kill by 1.5 seconds for that reason is unacceptable. On the other hand her ultimate can "crit", dealing double damage to enemies below 30% of their HP, resulting in high burst damage, like her E. So her kit is a spammy ability, a charm preparation, a bursty dash and a bursty AoE that also makes her blink back. This mix makes her Q feel useless other than a free charm, therefore wasting one entire ability for nothing.