They’re comparing actual exposure to estimated risk at that exposure.

Where? They refer to a 2003 study https://pubmed.ncbi.nlm.nih.gov/14600094/ with the conclusion:

Conclusions: Exposure to formaldehyde may cause leukemia, particularly myeloid leukemia, in humans. However,results from other investigations are mixed,

Apparently they were unable to find further studies to support their claim where they state as FACT that causes myeloid!!

It is a chemical so pervasive that a new analysis by ProPublica found it exposes everyone to elevated risks of developing cancer no matter where they live.

This is not true. Except counting naturally occurring formaldehyde, which indeed is everywhere, but not enough to make you sick, because we evolved in it!

perhaps most worrisome, it often poses the greatest risk in the one place people feel safest: inside their homes.

This may be somewhat true, which is why you must always let the air out of your home twice a day. But that's not because of formaldehyde alone. Also CO2 can build up, and radon can sieve in from below too. That formaldehyde is partially naturally occurring, and in homes come mostly from wood. If you have a lot of chipped wood, it has more because the glue used to make chipped wood contain it too. But this is regulated so products meet safety standards.

We had the debate here in Denmark in the 70's, claiming this 40 year old problem is suddenly an emergency that kill more people than any other pollutant is dishonest and sensationalist.

Outdoor air is often suffused with formaldehyde gas from cars, smoke, factories, and oil and gas extraction, sometimes at worrying levels

https://en.wikipedia.org/wiki/Formaldehyde

Processes in the upper atmosphere contribute more than 80% of the total formaldehyde in the environment.

Conveniently this scare piece does not mention at all, that most formaldehyde is naturally occurring!!!

Also from the Wiki:

Formaldehyde and its adducts are ubiquitous (all over) in nature. Food may contain formaldehyde at levels 1–100 mg/kg

Which the article also completely omit to mention, it is more misleading than informative.

Again: https://www.epa.gov/formaldehyde/laws-and-regulations-concerning-formaldehyde

Categories which formaldehyde is regulated under the NESHAP:
Plywood and composite wood products
Vehicle emissions
Wet formed fiber glass mat production
Mineral wool production
Wool fiberglass manufacturing
Manufacture of amino/phenolic resins
Wood furniture manufacturing operations
Rubber tire manufacturing
Natural gas transmission and storage facilities
Synthetic organic chemical manufacturing industry
Organic liquid distribution operations
Taconite iron ore processing
Emissions for polyvinyl chloride and copolymers production

Notice that wood is included in those regulations.

Edit PS:
OK apparently some people think they know better, than someone who has followed this issue for 40 years.
Despite I'm pointing out decidedly dishonest reporting, including misrepresenting results of studies!!
However I slipped up a bit myself, and have made a couple edits for better accuracy.