You absolutely do need to be an attorney to file for trademark applications on behalf of someone else. To quote the USPTO, ["Under U.S. federal regulations, only attorneys licensed to practice law in the United States are permitted to represent you in a trademark matter before the USPTO. Foreign attorneys who are not licensed in the United States and non-attorneys cannot help you complete your application, sign documents for you, or take actions in your application for you.
The unauthorized practice of trademark law before the USPTO is a serious matter. Employing any individual who is not authorized to practice before the USPTO to represent you could result in your filing being rejected and may jeopardize the validity of any resulting registration."](https://www.uspto.gov/trademarks-getting-started/why-hire-private-trademark-attorney)
While copyrights are automatically granted to the creator (with some caveats), you may file your copyright with the United States Copyright Office which makes it easier to protect.
It may be unwise to call out other people, but it is unwise to offer services for which you are not licensed. I am not saying all the other providers are not licensed (some definitely are), but many state that they are not attorneys or state that only licensed in other countries. Some show their educational background which precludes them from being licensed US attorneys.
Given that this breaks the Code of Federal Regulations and severely jeopardizes the filings of the buyers, I believe this is a ToS violation.