Yes, some long existing metaverses do still exist without Meta. Second Life has been going so long that it preceded much of the mobile phone boom, and has probably lost out on growth due to not having a good mobile app. Previous efforts had not been that successful, but it does now look like they have something that is working quite well, and today’s phones also have a lot more RAM and CPU power than 5 or 10 years ago.
There is also a video demo at the linked article below, that shows it in action.
See https://nwn.blogs.com/nwn/2023/06/second-life-mobile-ios-android-preview.html