Being able to video-chat with an agent is not the same as in-person assistance, for the same reason that a Zoom call can't replace a dinner meeting or a quick pop into a colleague's office.
Humans have a natural tendency to feel more empathy for those they see in person -- those whom our brains fully recognize as flesh-and-blood people -- than for people we only engage with remotely, whether by email, by call, or by video chat. The closer to real interaction, the better -- I'd rather video chat with an agent than text one -- but when I need an agent to be flexible, or do me a favor, or go out of their way to make a complicated change or do some lengthy research to fix a reservation, I'd much rather that conversation be in person. Not only is the agent likely to be more sympathetic, but it's sometimes easier to convey a request in person than by phone, where the lack of visual cues can make a well-meaning or friendly question come off as a complaint or demand.
I've long had a hierarchy for engaging with airport agents, especially when I'm asking for something that's not an easy-to-execute, SOP request. My view is that agents are most flexible in the following order, assuming they have time to speak with you. From most to least accommodating:
1. At the gate
2. At the club
3. At a post-security customer service counter (can be very hit or miss)
4. At check-in
5. By phone (Premier agents)
6. By text
7. By email (the "Contact Us" feature)
I've never tried the video chat, but I assume it's either as or slightly less helpful than the 1K line. So, long story short, if I'm asking an agent to rebook me OAL, or to consider some atypical (but rational) re-routing, or to agree that a flight that's just "delayed" will probably be canceled, I'd much rather do it in person.