Only if viewed through rose-tinted nostalgia glasses. I have fond memories of FFXI and less-than-fond memories, but memories nonetheless of FFXIV 1.0 and that type of gameplay would not work today.
FFXI combat was menu navigating combat unless you made macros for everything. The game’s structure was less rigid, but every time players found a way to play that the devs didn’t like (remember manaburn?), the devs would nerf it. Pre-Abyssea during the peak of the game, most time spent playing was grinding your levels instead of doing actual content. You would spend hours upon hours pulling mobs to your little corner of the meta leveling spot until you reach cap. FFXI had a lot of neat open-world content, but most of it was spent camping and spawning NMs and HNMs for hours upon hours.
FFXIV 1.0 had a bad sort of fatigue system where every action cost resources and you would end up running out of TP or MP and just sit there waiting for it to come back. 1.23 is what most people refer to as the “golden age” of 1.0 where a lot was overhauled, but it was a stop-gap until Yoshi-P could redo the whole game. Physical damage jobs also had a “sweet spot” for damage depending on how close you were and even lancer and gladiator had different range limits they could hit things but it was more annoying than interesting. The color your gear was determined its sub stats.
Leves were originally supposed to be the main content of the game. People could grind FFXI-style but my friends and I ended up powerleveling all our classes to 50 since it didn’t take long and a level 50 could quit your party after pulling an entire zone and kill them all and everyone would get full exp. Other than NMs and the open dungeons, the open world was complete garbage. Gathering mechanics were neat but not the sort of thing you could do for an extended period of time. Now they’re Gold Saucer attractions.
The only things I would like to bring back from 1.0 are the interesting types of hard content like the body-piece AF fights, debilitating mobs with specific attacks from specific angles, and multi-layered dungeon raids like the old Dzaemel that required one group of people to handle skeletons and ghosts spawning while another part handled Batraal.
From FFXI, I would like to see horizontal gear progression. Burning Circles and Salvage were neat but I feel like Treasure Hunts zones generally scratch that itch. I liked how each expansion wasn’t necessarily a direct sequel to the previous and newer and underleveled players could still do some content of the new expansion until they needed to level up for later zones/content. The gigantic city-wide invasions of Aht Urghan were neat even though my poor PS2 couldn’t keep up.