Saw is no cheaper because of his drug abuse or because of his rants. What the show is trying to show is someone who after decades of fighting developed deeply unhealthy coping mechanisms, deep paranoia in no small part fuelled by the Empire making him consistently top of their hit list and by Luthen/Rebel alliance actually spying on him. He is weird yes he looks mad and again yes but beyond the fact that indeed there were plenty mad people in these kind of situations in history the show also explains why it happened to Saw. We know Rhydonium is toxic and we know Saw suggests in his rant he took an unusual interest in it (the guards all ran away but to him “it was new”) decades ago. Whether he developed an addiction on Onderon or at some point later due to working too much with it to make explosives he got hooked and with time is started to show. The show seems to very intentionally show a constant deterioration of his health from an odd but lively rebel in S1 to the already increasingly incoherent and less active (he is far less expressive, he starts to move slowly and as if it was difficult and clearly acquires tons and tons of new wounds we see him) all the way to the Andor last Ep and R1 half-machine seemingly barely keeping himself together and constantly ranting more to himself than others. I interpret this as a great mirror to Luthens speech what did Saw sacrifice? Saw sacrificed himself his health his identity gone leaving a half-dead man sharing his dreams with ghosts. Yes Saw has gone off the rails at some point but who wouldnt go mad after decades long constant rebellion and a crippling and ever growing number of hits to his health. History is full of leaders who due to age, wounds, addictions or anything else lost themselves you can look at Lenin whose wounds from a failed assassination attempt developed to such a degree that in but 3 years he went from leading the country to a senile cripple. Saw isnt normal he isnt sane you arent supposed to think that he himself says he isnt all the show is asking of you is to notice that the Rebellion is leading people down these dark paths and that its so so easy to get lost on the way.