trash.
30s ads is dumb decision.
Little trick that works for me. Go to the little "i" by the ad sign when it plays, and choose stop seeing this ad (most have 3 options). Once you do that you can chose an actual choice and it will automatically skip all ads, or you can choose cancel/stop and it will once again skip all ads.
It works for me but I know I tried on my friend's phone and it didn't work so try but there's a chance it doesn't work
Also you can just use an ad blocker.
for firefox, chrome (and opera) and edge
https://github.com/cleanlock/VideoAdBlockForTwitch
adblock and ublock stopped working for twitch but that one has been flawless so far