I am good at math. Not the really high end stuff, but y'know, I can handle calc, and geometry, and all manner of whacky algebra.
But I hate math in my games.
I hate it.
I'm writing adventures with high-CR NPCs, and in order for them to be even reasonably valid opponents I have to give them all magic items. It takes a long while, and is usually boring, and involves just typing 'blah blah blah' and changing +10 to +11. That doesn't seem like much, but doing it a lot makes me want to break my fingers so I have an excuse to stop.
Same with skill points. Too much math is required to design encounters for the current ruleset.
Here's my argument:
If you want characters of level X to have a +Y attack bonus, just give them a +Y attack bonus. Allow for one point of variation: their ability score modifier. Then you can also get away with having morale effects that buff attack bonus. That way it's easy to determine anyone's attack bonus, and you never have to keep track of more than three figures: base attack bonus, stat mod, and morale bonus.
Video games can have janky stuff like +37 swords, because they let computers do the math. In tabletop gaming, when you have encounters like one I was thrust into last weekend with two hostile clerics who buffed their team with prayer, bless, shield of faith, and divine favor -- and then got hit with a dispel magic -- you don't want to be juggling so many numbers.
Magic items can still exist, but seriously, in literature if someone pulls out a sword, they might say, "This is the blade of my ancestors. It is unnaturally sharp, and can strike down fell beasts." But they
never say, "And I compared it to my friend's ancestral sword, and his seems to be about 5% sharper."
Just have 'magic sword' as an on-off toggle. Season with special abilities to your preferred flavor.
I'm actually okay with having a game where the characters carry lots of magic items. (I'd hope there were rules built in so they're not necessary, but whatever). However, I don't want a game where magic items just give a stat boost. That's flippin' boring.
Here are some ideas for ways to fix the current magic item mentality. Note that all of these would obviously be rarer than the similar items in the current system.
Belt of Giant Strength - When you wear this, you have GIANT STRENGTH. You can lift things and wield weapons as if your size category was one larger (or two sizes, or three, etc.). These items are no longer commonplace, something every fighter has. Instead, if you see someone pick up a tree and use it as a melee weapon, you'll be impressed. No one is impressed when a dude with a girdle sticks you for one extra point of damage.
Gloves of Dexterity - Grants an extra attack, the ability to quickdraw, and snatch arrows.
Amulet of Health - You regenerate, representing that your wounds don't bleed. Might be best as a scabbard.
Amulet of Natural Armor -
Cloak of Resistance - If you make your save against an effect, the cloak completely negates it, and may reflect spells back at their casters.
Ring of Protection - When you concentrate, you hold out the ring and get +10 AC against a single attack each round, deflecting it away telekinetically.
And finally, to go with all of this, institute a rule that no character can benefit from more than three magic items at once, or else the conflicting magic cancels them all out. Or hell, 1 magic item at heroic, 2 at paragon, 3 at epic.
Name a fantasy hero from before 1970 who has more than 3 magic items. There are probably a few.
Now name one who wore a magic ring, a magic amulet, a magic belt, magic gloves, magic shoes, a magic shirt, a magic hat, a magic cloak, and magic armor, and carried three magic weapons.