Why aren’t my dried beans creamy?

Definitely do the overnight soak in salted water, to start with. Prior to using the Instant Pot, my go to method was to bake the beans in a covered casserole in the oven. It's an even all around heat, more gentle than stovetop, and you don't have to stir except when checking on the doneness. I usually bring them to boil on the stove, cover and put in a 325F oven for about a 45 minutes to an hour. Exact timing depends on the beans, how fresh they are, etc. Start checking at the 45 minute mark by fishing out a bean and cutting it in half. That gives you an idea about the texture, and how close to done you are. The beans are less likely to blow out this way, or turn to mush.

Something so seemingly simple, yet so tricky! I had the same issue last time I made black beans. Hoping to have better luck this very evening with cannellini beans. And apparently we're not alone! This has been a hotline question before: https://food52.com/hotline/42925-i-can-t-cook-beans
https://food52.com/hotline/27194-how-do-i-guarantee-a-tender-creamy-pot-of-cooked-dried-beans
Both of these have good resources in the comments. But it seems to me the biggest factor is how old the beans are. Better luck to both of us!

I cook beans at least once per week, they're a family favorite since my adult kids were toddlers; here's what I do:

Some dried beans are "fresher" than others. Make sure you are purchasing them from a store with good turnover (I purchase from Whole Foods; I've tried black beans from Trader Joe's but they never cooked through). Pick through and remove any split or cracked beans. Rinse in several changes of water.
I soak them overnight in SALTED water. Although older recipes will say not to do so, ignore that advice. Salting the soaking water strengthens the outer skin so that they won't split or blow out in cooking. You want them to remain whole.
Soak overnight. The next day, drain and put them in the pot, again with SALTED water (per Kenji Lopez-Alt) and some seasonings: a whole peeled onion, bay leaves, etc. This allows the flavor to permeate, and, provided they are not old, they will tenderize and be succulent. (don't add acids, like tomatoes, until fully cooked and tender). If you have a pressure cooker or Instant Pot, even better (I do about 12 minutes for pre-soaked beans in the IP).

If cooking on the stovetop, stir occasionally to prevent sticking; I listen to the "thud" they make as they hit the sides of the pan when I stir; it will change from a dull thud at the start of cooking to almost silent: a clue they are fully cooked. Test by cutting one or more beans with a small sharp knife; it should slice cleanly through and there should be no "al dente" opaque core in the middle. Then taste to see if they are done to your liking.