I've never found a rice cooker to be necessary. Just cover the rice with about an inch of water - i.e. the finger trick - bring it to a boil and then cover it and turn it off. The latent heat will cook it perfectly in about 20 minutes without any other thought.
That sounds nice and easy, but i fucked up my rice about a third of the time and it really deterred me from making much. I got a rice cooker 4 years ago, ooooh boy now i make rice at least twice a week. As simple as making rice seems, untill you get it, it just isnt that easy. Plus rice cookers are like 25 dollars. Definitely the most used extra appliance ive ever had.
I don't get it either, and I have tried both. My results in the Zojirushi are middling, and well below what I achieve on my stove. If I need a longer-cooking variety (like brown or black rice) done more quickly, then I use the Rice button on my Instant Pot. The Zojirushi takes minimum 60 minutes on any variety and the results are not as good as what I can do on my stove in 20 minutes. (Plus the Zojirushi has no timer, no status indicator, and no power button. To turn it on you plug it in.)
I'm actually the opposite. We relied heavily on our $25 rice cooker (and it's still nice sometimes) but recently I discovered that stove cooked rice with like actual ingredients in it isn't as difficult as I thought it would be. Total gamechanger and even though I love my plain white rice, it can be really nice to mix it up and do like a Greek or Mexican style rice.