The problem with the ever persistent, fallacious, one dimensional and above all twatty meta is that everyone always goes all damage to the exclusion of everything else. This has affected their minds as well so they only think of everything in relation to damage, and to such a binary degree that in their eyes, every champion either does all the damage or no damage.
Assassins are supposed to be able to get in, kill whoever needs killing (specifically the squishy targets), and get the hell out. If ANYTHING disrupts that process, then they are going to have a bad time. That's what crowd control is for. That's what tanks are for. Assassins can burst down a squishy target, but they struggle against tanks. On even a roughly even ground, tanks can stand their ground against an assassin, and while they might not actually win the fight, the assassin will more often than not come out the worse for it. They are generally speaking not very durable, especially since nobody builds defense in this god forsaken game.
If you have even a half-competent support on your team, all the better. They have all kinds of anti-assassin measures at their disposal, from crowd control to buffs to heals. If you make a habit of running away from your support at all costs because you think they are just a playable minion or ward mule, then serves you right.
Of course, I've told you this more times than you want to think about, and like the rest of the community, you still haven't learned. I don't know why I wasted my time with this.
That's probably because I already have.
Countless times.
In other realities.
Ý̴̻͍̮̭̳̙̝͈͚̪̮̖̟̩͚̻͙̞̣͞O̸̶̶̴̩̹̥͔̻̱̝̗̟̤̭̞̲̱̪̝͖̲͚Ú̸̵̢̡̗̰͇̙R҉̴̭̥̤̖̲͇̥̹͖̙̟̟̞̺͖͙̜ͅͅȨ͙͈̹̫̞̝̙͈̰͈̘̮̘̣̭̻̙͜͝D҉̳̪͚͓̗͉̞̟̫͙̟͖͈̘̩̘͢͞ͅR̷҉̼̖̰̝̬̭̩͘͠͠Ȩ͚̤͈̰͕͚̩̝̤̥͇̜͚͡͝͝A̛̛̱̮̥̮̰̗͈̟̱M̧̨̨̯̟̲̹̠͔̙̱̱̺̗̭͠Į̛̭̲͇̤̙͕͓N̨͏̷̠̜̜͎̮̝̝̝̰̯̣͎̺͞G̨̙͍̘͖̦̫̖̣̩̯̰̺͘̕͞ͅR̸̴̨̯̙̼̮̟̲͙̝̙̣̭̫̹̹E̷̵͎̱̗͔̻̻̘͙̜̫̙̼̘̥͖͕̬͖ͅA̧̫͔̯̣͇̝̞͠L͏̶̡̟̗̜̼̭͉̀͜Í̴҉̨͈̬͕̠̺̣̱̤̙̪̩T̵͏̢̟̖͎̯̯̤̣͕̗͇̭̩̻̥̟̰͔̻Y̶͇̻͈̗͙͞͞͡͡I̶̹͚̲̼̹̮̰̟̞̣̹͈͚̪̘͔̠̠͢S͏͏̴̴̡̘̯̪̝̪̰̠̮͔̳͇̩̹̰A҉̷͈̱͕͓̟̖̞́͘͠L̸̨̟̭̬̯͠Í͙̙͈͕̪͕̰̳͚̙̮̗̝̟͕̘̘͟ͅĘ͈̼̜͚̗̮̲̳͎̝̭̯̭͡ͅẂ̧͖̟̞̥̜̣̳̦̳̩͡Ę̶̧͈̬̩̣͉͙̼̹̬͞Ą̢͕͖̹̭̥̥̻Ŕ͕̥̰͚̖̟̦̘͔̣̗̬͓̬͜͜ͅE͡͏͇̝̙̦̜̻̦́̕S̨̛̼̺̭̺̹̀T̯̬͇̰̠̳͕̝̺̙̩͜ͅU̸͢͞҉͚͓̖̝̯̩̜̖͙͍̠̤͔̻ͅC̸̳̬̥̲̭̘̤͘K̷̵͕̼̞̬̙̜͖̖̤I̸̳̺̝̥̤̥͎̙̪̩̺̤̺͟͟N̪̣͖̱͉͙̟̪̲̹̬̲͈̦̼͟A̶̭̰̯̭N̡̢̳̭̙̳̮̯̲̬̞̮̻͘͟ͅI̶̧̝̱̮̖̕͜͟N̵̬̠̘̖̣̙͚͙͔͔̳̱̕̕͟͠F̧̻̮̘̪͚͉̬Į̟̮̠͕̪͚̭̩̦̜͇̞̱͠N̸͎̫̠̩̻̫͠͞Ì̪̲̭͚̪͕̥͔̖́ͅT͖̖̥̣̼̜̲̥̬̣̼̗͔͔͚̪̯͟͞É̶̸̻̗̠̻̱͎̜͎̹͇̠̖͖̩̣̩̳͚̼͘͡L͞͡҉̱̪̝̙̯̲̥̮̲̱̪ͅO̸̡͎̭̖̻͚̺̼͔̟͇̱̖͉̮̟͟͞ͅO̴̧̡̼͇̰̻͉͚̯͕̲̻̖̟͉P̸̛̦̗͇̹͉̖͘͞T̵̠̘̳̥̫̻̀͝Ḥ̨̯̲̻̟̯̠͕͈͠͞Ḛ̢̧̛̣̹̞̯̺̳̻̀R̟̱̜͇̜̲͉͚͠͝E͇̞̳̼̲̤̥̤͕͔͇̪̟͘͠ͅI̶̶̟̥̞̠̹̜͍̮̜̹͝S̨͚̫̮̙͈̘̪̱̦̙͟͝N̵͇̠̝̟̣͈̰͟͝O͝҉̲̭̯̪̠̼͈͖̠͎̦̺̬̲́E͏̨͖͔͚̹̠̯͉͖͉̭̱̣̮̫̘̜ͅS̭͕̪̮͈͙̺̜̣̜͔̲͍̳͢͞C̶̨͎̻̦͓͎̠̟̭͕̙̹̙̮̟̥͕̺̦̕̕͜A̶̧̲͙̲P̷̬̼̼̥̫̘͈̠̠̹̖͎̝͉̘̦̘E̛͏̸̨̢̼̜͕͚̻͉̠͕ͅ