It's a cult.
https://www.cta-usa.org/perspectives/opus-dei-cult
Founded by Franco supporter and Nazi sympathizer
Members of Opus Dei are expected to have spiritual directors and are advised not to make any life decisions without permission from their spiritual advisor.
Many of their practices are archaic and misogynistic such as having women (usually young women from underdeveloped countries seeking a better way of life) clean the men’s dorms after the men have gone to work and when they are not home. These women not only clean the facilities, but do the laundry as well as prepare, serve, and clean up the food. They often put in 14 hour days. This is where some of the allegations of human trafficking come from.
the group has a goal to have a “symbiotic relationship with government and society as a whole.” Further investigations indicate that they have taken great efforts to influence and in some cases take over political organizations, especially in the US. Many of the authors of Project 2025 are Opus Dei members.
we have 6 Catholic US Supreme Court Justices. (Imagine, for a moment, that it was 6 Methodist or Jewish or Muslim). 5 of the 6 are affiliated in some way or outright members of Opus Dei (membership is not public, though they are not supposed to lie if asked directly.) Leonard Leo, head of the Federalist Society that has advised the Republican Party on judges, is a member, as is Bill Barr, Steve Bannon and more. J.D. Vance was featured on the cover of their magazine when he became Catholic and his stated views are certainly in line with Opus Dei.