Why cheaters and smurfs will always be
Dealing with cheaters involves monetary investment. Unfortunately for the community its a monetary investment that is a net negative to a company, as it doesn't make you profit. This is something EA doesn't like to hear. 7 plus months now and it hasn't been addressed. Sooo they either don't want to spend the money to deal with the problem or they have the data to support player retention time hasn't changed therefore why spend the money. On top of this ,I doubt its as much, as they are cheaters, but I'd assume some must purchase skins, etc. Which EA likes. I mean cheaters got into their professional comps. How on top of it can you actually be.
As for smurfs lol the idea they are going to ban smurf accounts is probably the funniest thing they have done yet. You can't even deal with legit cheaters let alone people just making new accounts. Some of which you stated is legal, I.e rank grind content. So you can't deal with the cheaters, and now your somehow going to be able to not only deal with smurfs but than also differentiate between a legal vs non legal smirf account. The most important thing however is to remember its EA and money talks. If people are actually lacking enough intelligence to buy skins, heirlooms, etc. On smurf accounts, or multiple accounts. Why on earth would they ever ban you. Imagine buying the same item on 3 different accounts, to maybe be in a slightly easier lobby and I mean maybe.
SBMM = smurfing, this is why its gotten way out of hand on apex and other games that have implemented these matchmaking policies. And smurfing = $$$$$$$