The verdict
If a good part of your enquiries start in direct messages and one person is drowning in them, I'd pick Manychat. If your problem is slow, misread written communication with clients and colleagues, I'd pick Loom. For many B2B teams, Loom is the easier first step, because it has a free plan, needs no training and does not depend on another company's platform.
They also work together. A Loom video can be the offer that a Manychat flow sends in a private message. Neither replaces a CRM. Push the contacts Manychat captures into HubSpot or another system, and keep Loom recordings organised so the library stays useful.