I liked core mining only at its very earliest stages. I must admit that since abrasion laser nerf, followed by prices nerfs, I hardly ever touched core mining at all since, despite having 3 fully functional mining ships in my fleet(Small, med and large), wich two of them are G5 legacy bulids. Surely those are ones that might have the most layers of dust, since many years already passed since I used any of those.. I do recall also doing laser mining in triple hotspots when it was a thing as well, but only done it a bit, maybe not more than 1,5B before I was bored of it, but that was some EZ money, and suprisly "chilling" or even "relaxing" but in end, it got repeative too much.
The term profitable is meaningless in this game anyway.
Only but an new, fresh cmdrs, credits means something for some of them at thier begining, but basically anyone after few years and some hundreds or thousands hours, they all will have that, since any and all activity is enough to earn billions, if doing long enough, even if only by stealing memory chips, and selling these to bartender.
Still does mining comes even close to tritrium CG's or that wine holiday event in unreachable system that is very high above galaxy plane, in terms how many hundreds of millions per hour one can make... I think it did only at early core mining, but since nerfs ages ago already, mining is just more like relaxing than outright "profitsss" activity.