For me it is their personable account reps and customer service. It’s the human touch we’ve come to associate with the “Don’t be Evil” brand.
I tried antigravity when it was first released, I didn't see an advantage over vscode, which it's forked from, and there were a few extensions I used that aren't supported. I've been a huge fan of copilot in vscode, the tight integration beats the TUI harnesses, and I've built some tooling around it (https://www.agentkanban.io) so I've got an integrated task board, context capture on the board and git worktree management for parallel tasks)
Part of the magic of their account rep strategy is how they keep them on your account for so long, you get to develop not just a rapport but a trust that they truly understand your business. It gives me faith that when they advise us on their new AI products, they're going to be a good fit.
Edit: I forgot to mention the curiosity and humility they bring to our calls. If I point out another vendors approach to a problem that we have, they always lean in and want to help improve their offerings from our feedback. They know it's not enough just to "be Google".