Citi Credit Card 48-Month Bonus Rule: How It Works In Practice

Hello, I have another question.
As livin in Berlin/ Germany I am wondering about something.
As the US carriers make fair extra money with the Card business, why is it, that in Europe there is no such thing?
With the LH Business Gold card you have some perks and collect miles but that’s nothing compared to the Point game in the US. Why is that?

EU regulated interchange fees, there's basically far less money to be made by the card issuers inside the EU.

I screwed up when applying for an AA business card for spouse. Learned after we applied that my spouse received previous bonus less than 48 months by several months. I'm usually on top of things but this time I should have checked more carefully and was a bit miffed about it. We still went ahead and met the spend threshold regardless and Lo and behold, the 75,000 mile bonus was earned anyhow. So, it's not a perfect system. Only thing I can think of is since they now issue a separate number for business, maybe that had something to do with it?

Competition in the US is greater as well, and people who live off credit cards (sadly, that is an exceptionally high number in the USA) and carry monthly balances subsidize the wealthier Americans, who tend to have better credit, can afford the annual fees, and are in a better position to take advantage of the benefits of the cards that offer the higher signup bonuses and come with higher annual fees.

The EU (and UK) cap interline fees at 0.3%. In the US it is nearer 3%. The UK had many more points credit cards prior to this, for example. So, much of the problem (from a credit card afficionado) is EU legislation.

I currently have the Citi Strata Premier card. I got the signup bonus on this card long ago (way more that 48 months ago, like 7-8 years ago).

I do not have (and never had) the Citi Strata Elite card - but I'm flirting with applying now. Based on what's written here, if I apply for the Strata Elite card and get approved, I should be eligible for the signup bonus, and I would probably then close my Citi Strata Premier card. My question is about my availability for a signup bonus on another Strata Premier card later: would me getting the signup bonus on the Strata Elite card (now/soon) make me ineligible for getting a signup bonus again in, say, 6 months, if I apply for another Strata Premier card?

As I read this story, it seems you have taken great pains to stress that eligibility for each card's signup bonus is considered separately - so I think I could get the signup bonus for the Strata Elite card now, and a few months later (after closing my current Strata Premier), I should be able to apply for that same card again and be eligible for the SUB again even though I will have received another signup bonus for a card in the same "family". Am I understanding all that correctly? Each card has its own "48 month clock"? Thanks.