What YouTube is genuinely good at
The best Kannada channels are run by patient native speakers who care that you understand. Two things they do exceptionally well:
Pronunciation practice in isolation. If you cannot tell whether you're saying aagide or aagiddhe, a five-minute video of a native speaker repeating the word at three speeds is more useful than any textbook. YouTube wins on raw quantity of pronunciation modelling.
Spot-fixing specific problems. When you've got a question — how to politely refuse a second helping, what the difference between baruttini and baruttiddini actually is — there's almost always a video that addresses it directly. YouTube is the world's best Kannada FAQ.
For those two uses, the best paid course in the world will not beat free YouTube. You should bookmark a couple of channels regardless of what else you do.