A trademark is a mark that distinguishes one's own product from another's product, so a registered trademark can only be used as a mark. It is not possible to monopolize the trademarked words / phrases themselves. For example, even if your company's registered trademark is listed in the text on the website of another company, it does not infringe the trademark right if it is not listed in a prominent manner as a mark.
On the other hand, it is also a fact that the recognition that "using a registered trademark is infringement" has already taken root, so it can be thought that "cannot monopolize the phrase legally, but can expect a de facto monopoly."
It may be one of the management strategies to register a trademark in the expectations that rival companies will be atrophied "Don't ask for trouble."