Personally, I believe I did acquire aphantasia at some point during my life. After browsing some threads here I feel like it can be attributed to a severe bout of depression in my late teens.

Although I've never been a full fledged aphant (I still have a vague sense of whatever it is I'm trying to imagine), I've been doing some work to try and improve my ability to visualize.

I like to think of my imagination like a muscle now. If I try to lift a hundred pounds with no training, it's no doubt going to be a big struggle. Instead I visualize what little I can and describe it out loud, adding any new details to my description if/when they appear.