This seems very specific to a few regions, India mostly.
Google is doing a really good job catching and blocking spam as far as I'm concerned. Even scammers aren't trying their luck over RCS in any way significant compared to Telegram, WhatsApp, or even iMessage.
I get vastly less spam on RCS than I do on SMS or iMessage.
The main thing Apple/Google needs to fix is RCS group messaging where spammers change the name of the group message to "Apple" or the business they're trying to impersonate.
Google is doing a really good job catching and blocking spam as far as I'm concerned. Even scammers aren't trying their luck over RCS in any way significant compared to Telegram, WhatsApp, or even iMessage.