Important to note. It's not just Roblox, it's also Discord facilitating this.
https://www.youtube.com/watch?v=acIxnaImf7U

This guy created a bot that prematurely bans members of sexual Roblox RP servers from joining servers with kids. 180 million accounts were banned from accessing kid-friendly discord servers.
As a result he got death threats, and people started abandoning their RP accounts. Finally Discord themselves stepped in and banned his bot, saying that it was 'unfairly targeting the gay community'. Discord has long partnered with Roblox and almost all the child-grooming is happening on Roblox-affiliated discord servers.