I'm assuming you mean Gen 8 NatDex AG, but the answer is the same regardless. Generally, Pokémon tiered below AG/Ubers/OU aren't great in NDAG (there are exceptions, though, of course. Sceptile is not one of those exceptions). Here's why:
They're pitiful for a metagame like NDAG. 85 base Attack is not exactly groundbreaking, despite its literal ability to break the ground with Earthquake and its other helpful coverage options (as you mentioned). Its defenses and HP aren't amazing either, and its 120 Speed is quite nice, but not enough to justify its usage. Even with 252+ Attack EVs, it struggles to deal 25% on standard Necrozma-Dusk-Mane sets, which are everywhere (this spread is used on 34.249% of NDM, actually):
252+ Atk Sceptile Earthquake vs. 252 HP / 252+ Def Prism Armor Necrozma-Dusk-Mane: 82-97 (20.6 - 24.3%) -- guaranteed 5HKO
Meanwhile, even with absolutely zero Attack investment, NDM can 2HKO Sceptile.
0 Atk Necrozma-Dusk-Mane Sunsteel Strike vs. 4 HP / 0 Def Sceptile: 228-268 (80.8 - 95%) -- guaranteed 2HKO
It can't even 2HKO the most used Pokemon in the tier, Mega Rayquaza:
252+ Atk Sceptile Dragon Claw vs. 0 HP / 4 Def Rayquaza-Mega: 144-170 (41 - 48.4%) -- guaranteed 3HKO
And Mega Ray's Dragon Ascent does up to 425% on Sceptile.
252+ Atk Life Orb Rayquaza-Mega Dragon Ascent vs. 4 HP / 0 Def Sceptile: 1016-1201 (360.2 - 425.8%) -- guaranteed OHKO
There are so many more examples, but I think you get the point.
There are way better/more viable options
If you need a physical attacker, why not use Zacian-Crowned, Primal Groudon, Mega Rayquaza, Marshadow, or any other viable physical attacker? If you need a Grass-type physical attacker, well...you're out of luck. Besides Ferrothorn, who is a wall, there are no Grass-types in the NDAG viability rankings currently, as Grass isn't the best type for a metagame dominated by Flying-, Fire-, and Steel-types.
TL;DR, don't use Sceptile, it's outclassed and fragile; use a better physical attacker with a better typing.
NatDex AG Mega Thread -- Viability Rankings
Smogon Dex SwSh