"Its" is much easier to remember as possessive if you understand it's a possessive pronoun, like his, hers, ours, and theirs. No apostrophes in any of them.
I don't understand what you're saying about "mass" possessives. That never went away, except for people's who don't know how to do it correctly.
My partner took our microwave (an obnoxious thing I bought at a charity shop for $15) apart and wrapped the dinger-thing in a thick rubber band to muffle it, then put it all back together. It sounds so much more polite now, and he didn't have to cut any wires or otherwise fuss with the basic function.