Raiding people you know is perfectly fine. And setting up a raid chain is a great way for everyone involved to grow. But I would advise against raiding strangers you had no prior connection with. While most smaller streamers, who want to grow, wouldn’t mind the extra viewers, it can create a feeling of having to give something back. And that can be awkward for many.

And raiding people you don’t know and have significantly more viewers would often be received negatively. It’s almost the same as spamming your Twitch link in their chat.

I’m still new to everything so I can be wrong. I’ve raided various channels as a small streamer, usually people with the same number of viewers and playing the same game just so viewers can continue watching similar content. Never raided a big stream since I don’t want it to come off negatively but I think helping others and showing support even if you don’t know someone is fine. Just be sure to vet their stream before to make sure they’re someone you feel like you’d want to support. I’ve also asked viewers for people to raid which has helped in the process! Good luck on your journey!!