Based on online news reports and a couple of documentaries on the topic I’ve watched (Frontline, Netflix), the regulatory constraints mainly entailed having new airplane designs go through more extensive scrutiny, which would mean greater expenditures for the company.
In order to avoid this (and therefore stay competitive with Airbus), Boeing reported the MCAS program as merely a minor upgrade of the existing system, and subsequently failed to train pilots in its use properly.
If this is what you’re referring to, I feel like “mainly caused by regulatory contraints on design” is a reductive and slightly misleading take. Or is there some other information to support your claim?