After quitting caffeine I can now fall asleep fairly quickly everynight. For 20% it could be negative.

It could be dosage and timing.

Coffee also affects my sleep but I need it to fight off my depression to some extent. So I have found one cup (250ml) early in the morning doesn't affect my sleep.

I have also found, I can have one more cup on the days I go running! (Physical exercise has something to do with caffeine efect on body)

I have a personal rule of no caffeine after 4PM. It helps with sleep! (6 hours before sleep is the idea)

I wasn't aware of these things until few years ago but now I do and I hope this helps someone!

After "quitting" coffee I'm extremely tired the day after actually drinking coffee.

Since quitting caffeine if I have a cup of coffee I have an incredibly hard time falling asleep.

You asked for proposals, and that’s how I present this. Not as a fact. But it seems to me looking into acrylimides as it relates to coffee roasting processes and the finished product is not an entirely absurd line of scientific inquiry.

And they can have my coffee when they pry it from my cold dead hands.

I don't eat processed meat and excercise daily. I like my odds even with coffee. I was briefly involved in a personalized cancer medicine company and talked to the prof there. He said if you don't smoke, avoid bacon and walk/run a few times a week you have essentially done everything you could. The bacon thing made me curious and it turned out almost all processed meat has nitrite (nitrosamine) added, which is a carcinogenic element. So much so they in fact used it to induce cancer reliably in lab rats. As to why food industry uses it - it is still better than botulism. As of 2021 we still don't have effective meat preservatives.

"Rats fed dimethylurea and 0.3% sodium nitrite for 36 days developed tumours of CNS, heart, thymus, kidney or thyroid in all animals (Sander, 1970)." http://www.inchem.org/documents/jecfa/jecmono/v05je15.htm