That's true for all forms of crit unless you have 100% crit hit. It's always chance.

1AD doesn't make you lose out on that much compared to that 1% crit hit. 1AD won't help you last hit better and it usually won't be the difference between life/death. 1% crit chance, although remote, can make that difference. Which is why it's worth taking a Crit Mark on Ranged ADs, since they autoattack so much. I know at least two times from personal experience where that Crit Mark killed an enemy for me and won the trade. I can't say the same for that 1 AD.

But, back on topic, we are all agreed that the 1% crit hit chance is negligibly useless for Lee Sin.

still you can't know wheter the crit will come in a trade( where it is useful) or while last hitting...

You do significantly more autoattacks with ranged, which is why it is useful and you build into crit, so it does become useful anyway. Not so useful on Lee Sin who doesn't autoattack anywhere near as much and relies strongly on his abilities in the first place.

even on ranged it is meh...

A crit mark on a ranged AD? Sure, why not.

Crit mark on melee AD? Not that good. You won't be able to attack your lane opponent as safely as a ranged champion would, so the crit mark isn't that good.

probably you haven't noticed that with 0.93% chance to crit only 1/101 attacks will surely proc a critical strike( which you really can't know when it will be used). In the meanwhile the rest 100 hits could have +1 AD. 100*1 ad=100AD overall, which is more than your crit.

The attack speed quint was actually an accident. 1 Crit is better than 1 ad imo because when you do crit it will do more damage then the 1 constant damage. Also 1 more damage allmost makes no difference so just having the chance to hit higher is better.

No Black Cleaver?

no,no,no

1 extra AD is more useful than 1 random crit.
Why?
Because with 0,93% crit chance 1/101 will hit for sure. Wouldn't it be better if you had 1 more AD for the rest 100 attacks( =100 damage overall)?

Greater Quintessence of Attack Speed, why?

Take a look at this because there you can find information on how to make your guide more appealing to the reader with the use of pictures and structual text formats.

This is a really good guide. I'm gonna make this into a Item build.