When sending an invite request, you do not receive any form of feedback as to what is done with your request. The only feedback you can receive is the notification of an invite when it is accepted by the recipient. More than often users are busy and cannot accept invite requests, the lack of feedback and information for user sending the request can impact the VRChat experience for that user negatively.
A comparison can be made to a phone call where the receiver can only accept or let it ring.
Users who may suffer through depression, anxiety or other issues that are related to insecurity often feel left out and users receiving the requests are often are blamed for ignoring users who send the request. The user receiving the invite request could be in a conversation, streaming, afk, RP, testing and many more reasons.
I have reason to believe that by simply giving the users who are using the invite system more information about what they're doing that users would be able to communicate with each other better and prevent unnecessary misunderstandings.
The most basic solution would be a status that every messaging app has: Available/Busy. Though this wouldn't be enough to solve the issue as nothing changes in the interaction that occurs between two users using the invite system.
A more thorough solution would be similar to how smart-phones give you the option to send a pre-made or custom message to the caller such as "I'm busy right now, talk later"
If the solutions above are not appealing, anything is better than nothing for those with insecurity issues. That way they are not left to their own thoughts to wonder endlessly why things are happening the way they are.