If you're looking for an authentic revival, stay on novetus, they have a discord server where people can host any games they want, however, if you want something "active", your best bet will be retrostudio, now, If you don't like either roblox vanilla or any novetus-based revivals, I cannot say pretty much more, because most revivals are either already shut down or just beginner people making shitvivals and sponsoring it on reddit (ahem, "tanobe"), also, when a new "big" revival is announced to the public, they sometimes shut it down after a month or a week of activity, If you're tired of waiting for another big roblox revival, you have 2 options:
1. Make your very own revival by yourself, host the client, the website, the catalogue, forums, etc...
2. Go find another hobby/interest In the meantime, you're just wasting your time finding a way to play old roblox