I think the Variants will save 5E. There is a lot of clutter.
Races. Giving ability increases leads to meta-gaming certain races for certain classes. Smart players will never try a different race.
Classes. Awarding proficiencies to certain abilities makes no sense. Why are Wizards proficient in Wisdom?
Warlocks have too many different features to track.
Starting equipment is disorganized and cluttered. Some of the lists are in alphabetical order and some are not.
Spells are poorly conceived. Range and Radius is very arbitrary. Spell damage also was not considered at all. Cantrips and higher level Slot Spells were not considered.
Multi-Classing needs to be reworked.
Monsters need more reactions to make them more interesting.
The CR is just random. There are formulas but the monster manual and the adventure modules don't follow them.
Attack rolls and DC rolls are often miscalculated by 1 or more.
Polymorph doesn't work but I offer suggestions about that.
Still a lot of potential.
Here are some variants I've been working on that address many of these issues already.
Select the Race of your Character.
Dwarf
Common, Dwarvish
Poison Resistance, SaveVsPoison@Advantage
DarkVision 60 ft.
Medium 5x5 ft.
Speed 25 ft.
Halfling
Common, Halfling
SaveVsFear@Advantage
MovesThroughLargerBeingSpace,HidesBehindLargerBeing
Small 2.5x2.5 ft.
Speed 25 ft.
Human
Common and 1 language
SaveVsPoison or Fear or Charm@Advantage
1 Level-Up Reward
Medium 5x5 ft.
Speed 30 ft.
Elf
Common, Elvish
SaveVsCharm@Advantage, ImmuneSleep
DarkVision 60 ft.
Medium 5x5 ft.
Speed 30 ft.
Select the Class of your character.
Martial
Str+1
StrRolls+ProficiencyBonus
Proficient with heavy armor.
Expertise in Athletics and proficient in 1 other skill.
12+con mod at 1st level
1d12(or 7)+con mod every higher level
1d12+strMod two-handed weapon damage
1d6+strMod primary weapon damage
1d6 secondary weapon damage
Skilled
Dex+1
DexRolls+ProficiencyBonus
Proficient with leather armor.
(Ranger)Expertise in Survival and proficient in 3 other skills.
(Rogue)Expertise in Stealth and proficient in 3 other skills.
10+con mod at 1st level
1d10(or 6)+con mod every higher level
1d10+dexMod two-handed weapon damage
1d6+dexMod primary weapon damage
1d4 secondary weapon damage
Mixed
Wis+1
WizRolls+ProficiencyBonus
Proficient with up to chain armor.
Expertise in Religion and proficient in 1 other skill.
8+con mod at 1st level
1d8(or 5)+con mod every higher level
two-handed weapon damage 1d8+dexMod
1d4+dexMod primary weapon damage
1d4 secondary weapon damage
or 1d8 spell damage to 1 target
Casting
Int+1
IntRolls+ProficiencyBonus
Proficient with abjuration spells/jewelry and light weapons.
Expertise in Arcana and proficient in 1 other skill.
6+con mod at 1st level,
1d6(or 4)+con mod every higher level
1d6+dexMod two-handed weapon damage
1d4+dexMod weapon damage
or 1d6 spell damage to all area targets
Multi-Classing
If a Martial class learns more than 3 skills, the Martial class goes to the Skill class table.
If a Martial class learns a spell, the Martial class goes to the Mixed class table.
If a Casting class wants to use heavier weapons, the Casting class goes the Mixed class table.
If any class wants to cast area spells, they go to the Casting class table.
Spell Guidelines
Spell Range starts at 30 ft.
Spell Range increases by +5 ft./lvl after 1st lvl
Spell Area starts at 10x10 ft.
Spell Area increases by +5 ft. at 5th, 10th, 15th lvl
A spell on 1 target is an at will Cantrip.
An area spell starts at 1 area spell per rest.
An area spell increases to +1 area spell/rest at 5th, 10th, 15th lvl
Spell Damage increases by 1d at 5th, 10th, 15th lvl
All saves on further turns happen at the beginning of the target's turn.
i.e. a 5th lvl Wizard can use Mage Hand to lift 15x15 cubic feet of objects 50 ft. away.
He can hit 1 target with 2d6 force damage every turn, knocking the target 10 ft. back.
Or he can hit 15x15 cubic feet of targets twice per encounter doing 2d6 force damage, knocking all targets 10 ft back.
Polymorph Object
You can alter armor and weapons.
+1 or -1 to AC
+1 or -1 at 5th, 10th, 15th lvl
or
+1 or -1 to Weapon Damage
+1 or -1 at 5th, 10th, 15th lvl
Polymorph Ally or Enemy
one size up or down
+one size every 5th, 11th, 15th lvl
Tiny Str-2, Dex+2
Small Str-1, Dex+1
Large Str+1, Dex-1
Huge Str+2, Dex-2
or
Water Breathing
or
Darkvision
or
Disguise Self or Ally
Polymorph Enemy to Object
DC+your magic ability mod vs enemy Con
Target fails or wins save, target will roll save again at the beginning of its next turn.
Another failure and the Enemy has the Helpless damage condition.
Two successful saves, the Polymorph fails.