OP - I'm not sure if you're looking for info on the different dining plans, or simply wondering whether the standard dining plan is a better value than paying out of pocket for each meal.
I just got back from a trip with 12 people of varyig family makeups. We all got the dining plan (paid for since we were unfortunately in one of the October weeks where
free dining was not offered) Despite my telling other families i advance that the dining plan is not necessarily wise for everyone, they all got it anyway. Here's how it stacked up for us:
Family 1 - 2 seniors with modest to small appetities. They thought it was too much food. They do not regularly eat 3 meals a day and definintely didn't want dessert with every meal that they DO eat. They either over-indulged because it was included or wasted soe snack or meal credits. Enjoyed watching the grandkids at the character buffets, but got tired of eating at buffets

Financially not a win, and they din't like that they "ate too much"
Fmily 2 - 1 adult on her own. Just about broke even and loved the "don't have to think about it" factor. Drinks soft drinks at every meal, enjoyed splurging on desserts on vacation, used snack credits for a pastry or yogurt for breakfat most days.
Family 3 - 2 adults, 1 picky child, 1 "infant" 2-year old who doesn't pay for the dining plan. Didn't like their restricted choices, complained about what they paid for a kid to "only eat a few bites" of something, Although that was often at buffets and really not different from life in the "real world" where you never know if your kid will devour everything in sight or just nibble on free bread! These adults usually only drink water, may have often ordered only an app instad of an entree if not on the plan, and the picky kids didn't get much value from their meals. Definitely a financial loss vs. paying out of pocket.
FAmily 4 - 2 adults, 1 disney adult with a moderate appetite, 1 child who's a big eater, 1 child who's hit or miss. Definitely a savings for us. Our table service places were often character buffets, which are expensive and the savings is dramatic for kids on the plan. We used most of our snack credits for a quick breakfast item, the Disney adult/teen couldn't quite finish her adult entrees but could share with the 9 year-old whose child meals weren't quite enough. Adults shared our desserts with the kids, who don't get one on the plan. We are all get soft drinks or tea with our meals and didn't have to make a point to use up any leftover credits or anything. A financial savings for us and we really enjoyed not having the sticker shock at the end of each meal.
Without the dining plan, we wouldn't have made as many character ADRs, which was a part of our park day, so I would count that as a negative to dropping it. Financially, only the single traveler broke even and my family with kids balanced out the potential over-payment of ordering dessserts we otherwise wouldn't get and we saved money compared to following our exact dining without using the plan.
I think the "out of sight out of mind" factor is significant and would recommend perusing menus and using online calculators to see if the dining plan is a good financial choice. Generally, having kids who actually eat combined with expensive buffet meals makes the dining plan a decent choice. The more you eliminate beverages, desserts, or choose cheaper menu locations, the less you stand to save.