I basically agree. With the ability prune in Stormblood, low level play became even worse than it already was. For example with MNK, if you had already unlocked Blood for Blood then you could start using it as soon as you had a cross-class slot. Now MNK doesn't get their big damage cooldown until level 68.
Because of the need to add new abilities with each expansion but also keep the total amount of abilities about the same to constrain complexity, we end up with this situation where skill acquisition gets spread further and further out and low level play becomes more and more miserable.
However a big part of this problem is because so many of the existing skillsets are back-loaded, that is to say, almost half your entire job is learned after level 50. A typical job gets about 25-28 actions excluding cross-roles, but because the devs feel there's this weird need to have constant new ability unlocks every 2 levels after 50, around 8-10 of those will be unlocked once you're already significantly well into the game. Not only does this make jobs feel horribly incomplete before very high levels (even max level for some jobs), but it causes a problem where you suddenly have to relearn your entire job after unlocking some key skill at high level, even though you've already spent dozens of hours learning the initial rotation.
Considering we're rapidly approaching the next expansion which will most likely be looking to raise the level cap to 80, and Yoshida has already said that they will be pruning skills again to make room for new ones, this is an issue that needs to be considered as soon as possible to avoid falling into the same trap and making low-level gameplay even worse than it currently is.
Simply put, skill acquisition rates and orders need to be drastically changed such that jobs are practically complete by the time they reach level 50. A job's entire basic rotation and core skills should all be in place by level 50, and levels 50-80 should see a dramatic reduction in the total amount of new skills learned (10 at most for the entire 50-80 span, ideally more like 6-8), and those new skills should not greatly alter the existing rotation except to expand on it with new cooldowns or traits.
You don't need to have loads of new skills to motivate people to reach the level cap, they are going to do that no matter what. The sacrifice of not getting so many new skills at high level is DEFINITELY worth the advantage of making low level and synced gameplay much more fun. One of the biggest complaints I hear about XIV from new players and veterans alike is that the combat takes FOREVER to get interesting. Locking away half the job toolkits behind level 50 (which for a new player will take them possibly over 100 hours of MSQ) is a huge turn-off, both for new players and veterans trying to level new jobs or do synced content. If XIV wants to keep retaining players this is something that desperately needs to be addressed in 5.0.