i think hypnos is one of the best modern/alt r&b albums released not just this decade but like all time. also up there is ctrl by sza (i only listen to the deluxe now) and when i get home by solange.
for 90s/00s r&b check out: toni braxton, tlc, usher, swv, destiny’s child, tamia, faith evans, brandy, brownstone, ginuwine, ms lauryn hill, mary j blige, beyoncé, bobby v, alicia keys, janet jackson, aaliyah, total, mary mary, kirk franklin
newer r&b: umi, summer walker, coco jones, normani, josh levi, lucky daye, flo, jasmine sullivan, victoria monét, kelela, tinashe, steve lacy, blood orange, brent faiyaz, leon thomas, ari lennox, syd, the internet, cleo sol
some of these artists can be more gospel, soul or electronic oriented but all incredible musicians