FF14 is actually a lot more forgiving of that more casual gameplay style. It's very easy to gear up after a break for anything outside of Savage and Ultimate raiding (and even then, you can buy or craft the week 1 gear if you want to get into Savage), the dungeon roulette system makes it so it's generally always possible to find people to complete content with, even if it's older, and unless you want to get into housing there's not really any penalty for say subbing for one month, taking a break afterwards and then coming back when you have time to play, outside of missing out on seasonal events (and generally any exclusives you get from those events get put on the cash shop the following year).

Also, FFXI player here as well, the ability for that game to run on low speed connections was frankly impressive for the time. I remember playing it using an infrared GPRS data connection on my laptop 😂 Sure it lagged a bit in city areas but the fact that it was still playable was a feat.