It’s true that most MCs are due to chromosome abnormalities, but stating that lifestyle factors cannot contribute to miscarriage risk is false.
https://americanpregnancy.org/pregnancy-health/caffeine-during-pregnancy/
https://www.parenting.com/article/seven-most-common-miscarriage-causes
Regarding coffee, the first article clearly stated that the studies regarding caffeine use were inconclusive, so they recommended limiting caffeine as a pre-caution. Not that it caused miscarriage.
The second article (after it mostly discussed chromosomal problems and other body issues such as immune disorders and cervixes) had a tiny paragraph where it discussed a few lifestyle things such as women working in different workstations where there seemed to be a higher rate of miscarriage but that they could not find clear links.
Correlation does not equate causation.
As for smoking, well... everyone knows that's bad for you, regardless. So..
Anyway, If a woman chooses to limit/abstain from certain things during her pregnancy, that is certainly her choice. But I am very tired of all the fearmongering, stress, women-blaming, and self-blaming that has unfortunately become part of "pregnancy culture" in recent years. Every day there is another thing that *may* cause problems, and people fly into a panic.
Use every day common sense, listen to your body, and hopefully you will have a stress-free, non-problematic pregnancy.