First thing to look at is our population density; it's been proven to create many stress diseases;

[ncbi.nlm.nih.gov] Population density and Social pathology; "the more crowded it gets, the crazier we become"

And we're growing at the rate of 150 more births, than deaths, per minute. 216,000 more per day, 1,512,000 per week. It's not quite the pace it was when it peaked in the 1980's - we're gradually getting our "family planning" act together....but I predict it's too little, too late.

Next thing to look at is the Per capita (latin for per person, average) rate.

Per capita, the highest cancer rate is in Australia;

[wcrf.org]

Per capita, the highest. autism. rate is in Hong Kong;

[statista.com]

Be aware; it's our overall growth rate that's not only causing our lifetime limit to level off (the U.S. is presently leveling off at age 81) - it's our proximity to each other. All of us are closer - so we share more diseases faster, and the diseases we share evolve more quickly. This social distancing thing is working, as are masks and vaccines...but the next pandemic will make this one look like a "walk in the park".

We will go extinct -it's not a matter of "if" it's a matter of when.

[worldometers.info]

there is also actually science that diagnoses what ails us vs the old approach of sacrificing a goat or two

That:
Explains Cancer.
Does not explain Autism.
"Why is there more disease" is 100% false and therefore can/should not be explained.