"It is not always necessarily the chemistry that harms us. Sometimes it's the shape and the presence of foreign particles in our bodies," (https://medicalxpress.com/news/2020-08-autopsies-microplasti...)
It's too soon to say what health impacts these plastics in our own bodies are having which makes it far far too early to have any confidence that there are none.
Personally it seems far more likely to me that globally observed health issues are caused by the proliferation of chemicals in everyday life that we know are definitely toxic. So IMHO an excellent plastic to blame if you need one is e.g. PVC (and also PTFE because OH BOY WHAT A SMART IDEA TO PUT THAT SHIT ON PANS WHAT COULD POSSIBLY GO WRONG I HAVE NO IDEA).
(This part made me laugh a little: "Microplastics are plastic fragments less than 5 millimeters in diameter, or about 0.2 inches, barely visible to the human eye. ")
In fact, the monomers of PE and PP (ethylene and propene) are also not toxic, which is uncommon (compare with e.g. PVC: vinylchloride is toxic in all sorts of ways, polystyrol: styrene is also toxic in a few ways and damages DNA, teflon: it's monomer is also a carcinogen). This is important, because making plastics generally leaves precursors in the finished product: the more the worse the process control is, which costs money and requires know-how.
See e.g. https://pubmed.ncbi.nlm.nih.gov/23862761/ for a study looking at whether these are EDC; they're not: "There were no significant differences between test and control groups in vagina or uterine weight. Data suggest that effluents from plastic food containers do not appear to produce significant adverse effects according to Hershberger and uterotrophic assays."
The single most problematic plastic for health purposes is PVC. PVC in its chemically pure form (difficult to do) isn't bad, either. But pure PVC is a hard, brittle plastic, which is not that useful. So most PVC products consist of a large portion of plasticizer; some products (e.g. cables and other types of very soft PVC) are actually more plasticizer than PVC both by weight and volume. Both PVC and toxic paints are a popular choice for all kinds of toys.