New job is one reason; the other part is to experience new looks, new lore. It’s particularly appealing to FFXIV players who lean on the roleplay side, it’s why the bestseller of Square’s exceptionally large cash shop is Fantasia, last I checked. In FFXIV, as I’ve said before, you would think they would be more lax on customizations as a result–but Square does so love their microtransactions. And as much as some people don’t like hearing it, one of their new races is required, without a disclaimer, to spend $$$ for customization that all other races can get for 2k gil–because the devs rushed the models for Shadowbringers. There has been no update on that situation for two years. They are banking on a situation they themselves created. That is a terrible look on any company.
TL;DR: I have never felt more keenly aware of a game trying to milk me for microtransactions on top of my sub than I have playing FFXIV.
Customization aside–alts in general are a grind, make no mistake. But in the leveling of one, WoW is easier in the journey in both aspects.
You can level all jobs on one character in FFXIV, yes. Your first job will complete the MSQ, unless you switched over to another, but all in all, your MSQ will be gone before you leveled all the jobs available. Sidequests you may have skipped along the way will still be used up before you have leveled all the jobs available. New Game Plus gives no exp and no rewards; it’s just a story replay.
You now are stuck in a seemingly endless grind of deep dungeon dives (Palace Of The Dead and Heaven-On-High, which make Torghast look really nice) and the same dungeons/raids via roulette, to level all the rest. The Main Scenario gives some of the best exp, esp. if you get Praetorium. Except Praetorium also has a mandatory one hour and five minutes roughly of unskippable cutscenes, every time.
Rested time is shared between PvE and DoH (crafting). Leveled that baby 20 CRP a bit? You just blew all the rested exp for your 50 RDM. Warcraft gathering uses rested exp, too, but it gives you PvE exp. In FFXIV, Gathering only levels Gathering.
The repetition gets very, very old, very fast, and with the number of jobs available, it is very, very boring. (PotD groups can also be some of the most ill-tempered, new player unfriendly pits I’ve seen in any MMO. They don’t care you need those silver chests to level your Aetherpool stats, and they will let you know it just enough to skirt outright harassment.) That’s one of the things that make me laugh when people swear the FFXIV community isn’t toxic. They definitely are, they are just afraid of losing their accounts because the GMs are ruthless with the banhammer. As a result, the bads are kings and queens of passive-aggressive badgering in-game–and no better than any other MMO community in private channels. Or Warcraft forums.
In Warcraft, I can roll a fresh alt, and thanks to Chromie, I can level in any xpac, questing in places I haven’t seen before, learn new things about the world and characters. It’s great for would-be loremasters. The leveling is exceptionally fast, and for me it always stays fresh. Queue times are rarely noticeably long, even for DPS classes, and I quest while I wait–and thanks to Warcraft being far more friendly with accountbound things, it just feels like an extension of my main. And boom–I have my desired new look, new lore, without spending a dime, and the time cost is far less tedious. And even for that race, what would cost me $$$$ to change in FFXIV? In-game silver at the barbershop.