But this is one of the great things of this hobby:
1. There are thousands of systems to select from.
2. No one forces you to play it RAW.
3. If you do want RAW, you can probably find a system that works for you.
The most important parts are: what's fun and conveys the sense you want for the game; agreeing on the rules (either RAW or house) with some consistency (What do you mean I can't jump down 10'? You let him jump off a 50' cliff without getting hurt just last week!).
https://olddungeonmaster.com/2014/08/30/bounded-accuracy/
The TL;DR is that AC/attack bonuses/saving throws/save DCs used to scale a lot more than they do now. The upshot of this change as a DM is that you can plan out encounters differently. Feel like your first-level characters aren't getting enough of a workout? Throw a CR 3 or 4 encounter at them. I ran Curse of Strahd as my very first 5th Edition campaign, and there was an encounter at the end of the early section where I'm like, they already lost one character earlier in the dungeon, this is a straight-up TPK. But they handled it fine, although they used about a day's worth of abilities/spells that recharge with a long rest in a single encounter. That's where I started to get a much better feel for how encounter balance works in 5e.
Well, compared to the “classic” versions (through, oh, AD&D/2e), 5e’s handling of cantrips and assignment of hit dice to classes make the primary casters more active and less like eggshells at low levels, and healing outside of “healer” character abilities is much more generous by default (but there is also, in the books, a simple option that makes it grittier reverses all of that except the not-eggshells parts, by increasing the time for “short rests” and “long rests” which are key for both healing and spell recovery.) Also, I feel like lots of tables by people who come from older versions underuse exhaustion.