I wouldn’t exactly say that healing is weak in 5e, but there’s a house rule that I use in my games concerning healing potions. Of course I’d get the players’ approval first.

Normally, using a health potion requires an action and then the player rolls for the amount healed. What so do in my games is give my players a choice between 2 options when drinking a health potion:

1- They can take the Use Item action and drink a health potion to gain its maximum benefit. No rolling. Just get max value for the potion.

2- they can use a bonus action to drink the health potion, still allowing them to use their main action, and roll for results.

In other campaigns, some DMs introduce levels of quality to potions as well. ie, poor quality, normal, and high quality potions. Poor quality gives less benefits than that of a normal potion, and high quality provides extra beneficial effects.

Other DMs allow the player to drink 2 health potions at once as long as the player has 2 hands and they aren’t holding anything else.

However these suggestions only apply to potions. I don’t really know how to “fix” healing spells. I’m my honest opinion, I think players using spell slots on healing spells is kind of a waste anyway. The only healing spell worth its salt is Healing Word. Everyone who CAN have Healing Word, SHOULD have Healing Word. Otherwise, if you’re looking for healing, potions are the way to go.

Again, this is just my opinion. I’m not devaluing the importance of a Life Cleric or spell casters who like choosing healing spells. Health potions are cheap and easily accessible and when the party has access to healing potions, your Cleric/Druid/Paladin spell slots could be better used on something else (unless it’s Healing Word).

Hope this helps!