Meeting up over lunch doesn't work for remote teams. Nothing worse than eating while on camera. No thank you, I've tried and it's really not great. Especially if you have a hybrid team where some people are in the office eating together in a conference room and some are remote solos, the dynamics get really weird.
One of the biggest benefits to a synchronous standup is you know everyone has showed up and is available to discuss work stuff. With remote teams and flexible schedules, having a hard sync point helps people communicate better, even if it's just "hey, let's stay on the call (or start a new one) for an extra 10 minutes to sort this out" instead of spending hours or days in async communication.