If they wanted to make browsers less secure, they would do so in much more obvious ways.

The new proposal demands browsers automatically trust government created root certificates. That means any EU government can do a man-in-the-middle attack on any end user running that web browser, even users in other countries. There is no reason to do that other than to spy on people or to manipulate the content that they're viewing.

If any government, or company for that matter, wants to make their own root cert and deploy it to all their users/machines they can already do that easily. A lot of companies that work with sensitive data already do this, and some companies (ex: symantec) provide solutions to do it very easily, so the IT team can see everything the users are doing.