Multiple Amex cards

I just got a second Amex platinum card. Do I have to wait 90 days before I can get a third Amex card? Or am I limited to 5 or 10 total Amex cards? I am confused on what I am reading online about charge and credit cards and which one all of the Amex cards fall under.

I am also wanting to get other Amex cards like another Hilton card or delta card and other non Amex cards. Would getting those cards prevent me from getting a different card? For example, would getting a delta Amex card restrict me from getting another platinum card in the future?

Also, would getting another brand card like Chase visa restrict me from getting another platinum in the future.