Yes, you are correct in that a single individual’s action will make no difference, just like your single vote makes no difference either. However if everyone does their part it can make a massive difference.
While your individual contribution makes no difference, you still should try to do your part. Yes, change takes work and a bit of sacrifice. Just like how it takes time out of your day to do research on candidates and go to the polls.
If you don’t do the work, it doesn’t make you smart or clever, it just makes you an asshole taking advantage of others.
It is likely not worth your effort as whatever you come up with will likely result in discord deactivating your account for breaking their ToS, or them breaking their API forcing you to constantly play catch-up.
This is why open communication protocols are so important. Email is still as ubiquitous as it is because it’s a protocol, not an API.
I personally think it would be less overall effort to get your friends to switch to an open protocol like matrix, or XMPP than it would playing cat and mouse with proprietary APIs. But you do you, I wish you the best of luck!