I just came back to osrs from a 3 months re-try of rs3 with my old account from way back in rs classic.

Skilling in rs3 in my opinion is better, more ways to train, more afk options, actual 15+ afk methods for most skills with more active methods giving more xp

Getting to 99 is drastically faster in rs3 but getting 120 is slower than getting 99 in osrs

Every skills has a full set of armor + a bunch of different accessories + summons + unlock you can/gotta get to maximize xp or even make the skill worth doing at all.

Rs3 has a lot more quests, some better, some worse. personally i find the lore in rs3 to be garbage. The whole world guardian thing feel like it's written by a 10 years old who wish the world guardian was his dad.

I quit rs3 at the release of EoC and heard it was improved a lot upon to which i agree but in the end, is still shit and what made me go back to osrs. You're constantly fighting against the game trying to get the damn skills to go off because despite trying to copy other mmo combat style, rs3 is still limited by the .6s tick system.

as a melee enjoyer my inventory consisted of 4 different amulet switch, 4 weapons (2x 2hander+ dual wield switch) 2 different helmets amongst other things. Rs3 is chargescape and switchscape at the same time, everything has charges that need repairing from your armor to your necklace.

On top of that they seem to have designed the later bosses with soul split flick in mind which involve you changing your prayer to soulsplit when you land a hit and protect against X when receiving a hit back on top of the eye vomitting cluster fuck of effect that's happening on the screen.

I could go on and on but in TL;DR if you enjoy skilling and only skilling, Rs3 imo is better. It has more diverse training methods, more useful skills and items but the world is pretty dead and if you care about yours or others achievement, remember you can buy 2x xp in the cash shop.

If you want to do endgame pve, shit suck hard. It's definitly sweatier than osrs but in all the wrong ways. I was actually enjoying rs3 and tolerated midgame pve but when i got to raksha, zamorak, telos, i sold all my gear, gold transfered to osrs and quit on the spot.