I'd be wary of this approach - either from issuers suspecting you are gaming the system, or the effect on your FICO score as the average age of your accounts decreases.
I might be totally off base, but this seems like it can't end well.
Two cards a year isn't even a blimp on most card issuers radar.
If you go to r/churning back a few years, people were getting 24 new cards a year. Open the card, buy $4,000 worth of gift certificates, claim the reward, close the card, repeat. It was insane the amount of effort people put into it.
Banks creates these rewards to incentivize people to open the cards. Chase did eventually put a limit of 5 cards in 24 months (a limit I have hit), but they just reject you for the card off the bat.
In terms of the credit score hit, it's minor. I've never had my score change by more than 5-10 points. I wouldn't do it if I was applying for a mortgage in the near term, but otherwise, it doesn't really change my score as 5-10 points doesn't change the band you're in.
Last I looked, I think there may be language in the cardmember agreement that exempts gift certificates and the like. E.g, this explicitly doesn't count and may get flagged for extra scrutiny.
I'm well aware of 5/24 -- I might suggest that if people are shuffling things around that much, they deal with Chase *first*, before looking at other issuers, just to be sure those applications don't get denied.
For me I just sign up for a new credit card twice a year and then shift my normal spending to the new card, canceling the old one.
I usually get a week’s hotel stay for free or $1000 cash back for nothing more than taking 30 minutes twice a year to find the best card.