This matter exists on the Pi network, and there is no monetary payment or greed involved. All you have to do is lock some of your coins in exchange for sending a message, and the amount increases as the importance of the person increases.

Time-based tokens, i.e., KOLs tokenizing their time, have recently resurfaced. Although various attempts have been made in the past, none have taken hold yet.
Instead of time, I have always wanted to optimize reach. LinkedIn, X, provides this ability, but the barrier is too low, resulting in a lot of spam, making them unusable.
Here is an idea for a platform that allows serious people to reach others.
A famous person (KOL) connects his X (or LinkedIn) to the platform, verifying who they are. He then sets a price for people to message him, say 1 or 0.1 BNB.
Anyone can message him/her by paying that amount first. If the KOL does not respond within 5 days, 50% of the paid amount is returned to the requester. There is still a cost to the requestor, which deters spamming and encourages them to write the message effectively.
The KOLs are incentivized to respond. They get paid 50% more.
Defaults based on my personal preference:
Max message length should be limited to 2000 characters, roughly a two-pager.No images. No attachments. (No virus downloads)
The requester can include his contact info in the message. If the KOL contacts them directly, he (and the platform) gets paid 50% less.
If the KOL wishes, he can reply with his contact info, and then the conversation can continue on a free messaging app.
The platform charges a 10% fee for all transactions. Payment-wise, the requestor pays crypto to the platform, which then splits 90% to the KOL’s provided address. 
No new token is needed.
No time-based tokens.
Hopefully, there is enough demand for such a platform to make it a sustainable business.
This might be a good way for KOLs or professional consultants to get paid for their responses.
I would use a platform like this. I will donate the crypto I receive to a charity. This helps filter out only serious people to reach me. I may move the conversation off the platform when the other party has something serious to offer, return the payment, or even give a bounty (for security tips, etc). I will then be able to open up my DM to everyone and adjust the price over time based on how unpopular I am.
This model doesn't solve all problems. Not to be arrogant, I'd imagine many scammers will be willing to pay 1 BNB to reach me.
YZiLabs may invest in a project that develops a good MVP using BNB/BSC as the primary payment option. It should take a few days/week of coding and a security review. I will be a first user, provided the platform is secure enough.
X, Linkedin, or Square could build this as a feature, but big companies move slow. Might be faster with a new site.
Just an idea for the weekend.