Are trading cards a form of gambling?

It’s the same concept loot boxes use to get around gambling laws, as long as you get “something” with every purchase its not considered gambling as you always “win”.

Yeah, I assumed the reason the ante cards were dropped was because most people hated playing for ante, didn’t play for ante and were subsequently annoyed by the ante cards in their pack.

That was certainly a major factor, as well as the concern about ante causing tournaments to be seen by legal authorities as gambling. As per the MtG wiki: