You have to manually chose a stake pool and delegate. It's not automatic because you have to pay a transaction to let the blockchain know that you delegate to XYZ pool. If it was automated it would mean that your wallet could do transactions on your behalf, and you don't want that.
Lots of good pools out there, don't choose the ones that have the most Ada, small pools can reward you very very well, just not as regularly than big ones
You have to manually chose a stake pool and delegate. It's not automatic because you have to pay a transaction to let the blockchain know that you delegate to XYZ pool. If it was automated it would mean that your wallet could do transactions on your behalf, and you don't want that. Lots of good pools out there, don't choose the ones that have the most Ada, small pools can reward you very very well, just not as regularly than big ones