I dont like current tome system because of two reasons:

1. Its extremely limited in what you can use it on, because of both 450 tome cap on collecting them per week and the fact that there are quite a lot of gear groups in the game. Latter especially applies to melee dps, since there are 3 separate gear groups, and if you buy, say, striking gear, you can't use it on 3 jobs out of 5 that role has.
2. It is pretty much "the weekly" that you have to do without missing any weeks if you want to grab your gear at earliest time. Missed one week because of reasons? Well, you just lost 450 tomes, and you cant catch up to that. Didn't cap, because you forgot/were busy with something else? Sucks to suck. New player that just got to lvl 90 and didn't cap tomes because you didnt know they are limited? Oopsie.
Yeah "capping them is easy", but thats something that would have to be addressed in case they made it less restricting on what you can buy per week

It obviously doesnt matter too much, because of how only raids and ex trials have any kind of use for equipment (and everything else having ilvl sync), but it still feels pretty bad.

The way i would probably prefer to see tomestone gear handled:
1. Remove weekly tomestone collection cap, and introduce "dynamic" cap on how much you can spend, that increases every week without resetting.
For example, week 1 will have 450 tome cap. Buy a piece of equipment for 200 tomes, and you sit on 200/450. Next week, you will be sitting on 200/900. Then 200/1350 etc etc.
This would fix the issue of losing weekly tomes if you werent able to collect them, while keeping "timegated" aspect of gearing up.

2. Separate it by roles (or even better, sub-roles as well, like DPS -> Melee DPS, Ranged DPS, Caster DPS)
It just something that really needs to happen at this point in some way. There are 7 gear groups in the game currently, and 450 limit for all of them just doesn't make any sense.

Those 2 changes, IMO, would make gearing up different roles with tome equipment way less tedious in a way that that doesnt make players feel that they "have" to farm all these tomes to not stay behind.