Abi-Dalzim's horrid wilting exists to give necromancer wizards a decently powerful direct damage spell that they can use to activate their Grim Harvest subclass feature. It patches a hole in the PHB spell list. It's also handy if you are facing down a copse of ornery treants. Non-necromancers...
I run combat on a grid almost exclusively, but I think that actually buying miniatures is a sucker's game. Instead I create cardstock tokens with exactly the art I want on them. This is not a $0 solution -- cardstock and printer ink are fairly expensive -- but it's much easier on the wallet than...
You still need the DM to play the ogres. And create the environments. And devise the traps. And invent the richly detailed NPCs in the nearby village whose grievous plight tugs on the PCs' tender heartstrings, prompting them to set off slaying ogres in the first place. In other words: the DM is...