I do it regularly, in fact I opened a new card expressly for buying xmas presents, knowing I’d spend $1k easy, might as well get $200 back.

Then I put the card in a drawer and forget about it and go back to using my preferred card.

The only downside is your credit score will drop a bit due to the credit pull, but that’ll go back up after a few months.

The key here is to pay it off in full otherwise interest is eating into the bonus.