The level of difficulty has absolutely changed with AST. Even when you didn't specifically go down the route of optimisation, at a base level you still had 4 offensive cards to dish out every 2 minutes, a redraw mechanic if you didn't get what you want, and also far more buttons to actually press and manage with Lord/Lady - especially when the 60s cooldown wasn't visible if you were sitting on a Lady. Astrodyne was an extra button you had to use to not overcap with your card usage too.

That's just the base level. Optimization would include moving 3 cards to your burst window and using Lightspeed to double weave between GCD's to get everything out - 3 cards, 2 Lords (if lucky), Astrodyne (x2 sometimes), divination, earthly star 10s+, etc.

You were punished with losing DPS if you didn't use your cards. Overwriting and not using your heal/mit cards does not punish you. The lack of RNG or a seal system makes every card scripted and fixed. Beyond the initial small learning curve of ''X draw = melee, Y draw = ranged'' you will not think about the cards anymore than giving it to the same person, over and over.

All of AST's healing will stay the same, so in terms of that, it will still be harder than WHM - but the card system alone being gutted has stripped a lot, if not, the majority of its difficulty. But I'd still rather play WHM with a better job mechanic.

So yeah, AST has definitely been made easier, it's why I've seen some casuals think the rework is phenomenal.