The progression is absolutely time gated, and they definitely calculate the travel time to make each zone take some given amount of time to complete. When they need to pad out the zone a bit longer they add one of the trailing quests (autoscroller). It’s the business model and the same reasoning for why they don’t increase the weekly tome cap and also why there’s a weekly loot lockout during the raid tier, if players could grind out all the gear they need for a patch in 1 week, they would. That said if all you want to do is the msq and normal content, you can probably beat that in 30-40 hours watching cutscenes if you can dedicate a weekend to it and unsub until the next patch. I finished the msq + all aether currents in about 16 hours after launch with a couple friends, skipping all cutscenes, and the leading edge progression groups were probably done in closer to 10-12 hours so they could hit the EX trials.
Midrange systems from 3-4 years ago are the ones that are struggling a little bit. It’s playable but noticeably slower. It can mostly be mitigated by turning all the bells and whistles off though, and I guess if we really wanted the extra frames we could turn down the resolution. But playing the game at 720p for instance is a serious disadvantage, theres not enough pixels to see your hud elements and the fight mechanics without a super ultrawide monitor or a zoom hack. 1080p is ok but 1440p or 4k are ideal