I guess I'll never have any answer.
Your so called question is just a feeling you have, opinion... Ever asked yourself that maybe it's not true and if you never played DnD 5e maybe you wouldn't feel this way.. What exactly is this thing that is now useless do to Height advantage or backstab in your opinion - feeling? One example will do...
I never played any TT
This is a part of what grants advantage or gives disadvantages in D&D.
You may still use some of them in the game, but for specific purpose (i.e you may fear an ennemy or use sleep, but this wouldn't be related to advantage).
General Actions:
1. Dodge/Help
2. Dropping Prone against Ranged Attacks
Spells:
3. True Strike
4. Vicious Mockery
5. Cause Fear
6. Command (certain instructions)
7. Compelled Duel
8. Ensnaring Strike
9. Entangle
10. Faerie Fire
11. Find Familiar (Help Action)
12. Fog Cloud (Depending on types of sight)
13. Grease
14. Guiding Bolt
15. Protection from Evil/Good (Against certain enemy types)
16. Sleep
17. Snare
18. Tasha's Hideous Laughter
19. Zephyr Strike
20. Blindness/Deafness
21. Blur
22. Darkness (Depending on types of sight)
23. Heat Metal
24. Hold Person
25. Invisibility
26. Maximilian's Earthen Grasp
27. Shadow Blade (Depending on lighting)
28. Web
Class Features:
29. Barbarian - Reckless Attack
30. Barbarian - Wolf Totem
31. Barbarian - Ancestral Protectors
32. Bard - Words of Terror
33. Cleric - Warding Flare
34. Cleric - Invoke Duplicity
35. Druid - Multiple Wildshape forms that grants Pack Tactics (Wolf, etc)
36. Fighter - Distracting Strike
37. Fighter - Feinting Attack
38. Fighter - Goading Attack
39. Fighter - Menacing Attack
40. Fighter - Trip Attack
41. Fighter - Fighting Spirit
42. Monk - Patient Defense
43. Monk - Open Hand Technique (knocked Prone)
44. Paladin - Conquering Presence
45. Paladin - Nature's Wrath
46. Paladin - Abjure Enemy
47. Paladin - Vow of Emnity
48. Paladin - Dreadful Aspect
49. Ranger - Umbral Sight
50. Rogue - Assassinate
51. Rogue - Master of Tactics
52. Rogue - Cunning Action (Stealth)
53. Sorcerer - Eyes of the Dark
54. Sorcerer - Tides of Chaos
55. Warlock - Hexblade's Curse
56. Warlock - Pact of the Chain (Help from Familiar)
Don't you read the threads you're answering to ?
https://forums.larian.com/ubbthreads.php?ubb=showflat&Number=719930&page=1