Living Story 4 rewards lacking.

By chapter 4 in LS3 there is enough choose your stat trinkets and backpacks, you can reasonably farm the HoT stats for multiple toons. As for this living story we've only gotten a backpack that requires 500 shards not including the other costs to repeat build. Then from Sandswept Isle one ring and earring. That means in order to get the sets one would need to do Fractals or PVP The only set you can complete of PoF stats is Plaguedoctor. This is very poor system of reward, compare this to Bitterfrost where within a few days I can get a backpack, ring, and earring of any stat except PoF specifics. The map currency in new maps is too spread out and doesn't reward playing in the new maps.

If you look at how these things were offered in LS3, you'd quickly realize they were trying to fix a situation they didn't actually think about during HOT's development. The high availability of choosy was to make up for the fact that only a hand full of Ascended Trinkets with HOT stats were possible to obtain across A WHOLE ACCOUNT, and Vipers (the most demanded one) was non-existent with the exception of One amulet.

POF stats are available in the Primary expansion via the same vendors that handle the exotics. And aside from the launch day snafu with Greving, the only limitation is LS4 specific stats being specific to LS4 maps. Thus there was never a shortage of Trinkets with certain stats for the "choosy" items to have to fix. Theres also going to be more then 6 episodes in total before the next expansion, which still gives a LOT of time for them to add more to the list, and offer duplicates. And if we're being honest, they don't want a repeat of LS3's "hyper valued" map farms, and have every reason to try and kill off Istan's farm with something thats not going to bend the economy with loot.

On top of which you already pointed out Mist Trinkets, which already address all the short falls being brought up. Mistakes were made in HOT, and LS3 was there way of rectifying that. That problem didn't happen in POF- and the universal nature of Mist Trinkets plus Mist Armor/Weapon rewards all being part of Core directly eliminates future shortages. Multiple options are given at this point, and the majority of them are merely asking you to either do one full cycle of rewards, or hammer out a daily (which takes all of 30-45 minutes) for a few weeks to get most of what you need.

Now if you want to look at it from a Meta perspective, the only game modes that really demand any of the POF stats are WvW and Raids... and its mostly limited to Harriers, unless you're experimenting with off-meta builds. DPS slots, which are by far the largest in population, are still heavily focused in HOT and Core (Vipers/Zerks); while WvW demanding 2 additional stats (Minstrels and Celestial), both of which are HOT and Core. Harriers can be bought directly from NPCs at the main cost of Brandsparks and Laurels (like any other Trinket in POF).

So to recap.... the problem in HOT that the LS3 trinkets had to fix doesn't exist in POF, the Devs are trying to avoid a repeat of Istan farm at the map level, are metering out the trinkets to cover the remaining episodes, many of which are running parallel to the Legendary Trinkets from the looks of it, and multiple other options of equal or greater accessibility exists for obtaining those stats. So ultimately the only thing stopping you from getting a full POF stat set of trinkets is the assumption that something they once did to overcompensate for a mistake is supposed to the new norm, and are not willing to spend the time to bang out dailies just to get it out of the way in the long term.

Reward types are way better in Season 4 then in 3.

We got one full armorset (upgradable even) and one full weaponset (also upgradable) and alot of stand-alone weaponskins!

Ascended trinkets are already easy and for many players it doesnt really give anything worthwhile to farm for.

From a gearing stand point yes, LWS3 is superior to LWS4 as far as trinkets goes. Arguably LWS3 is a tad to easy to get trinkets but you can't really change that now without being biased against newer players.

From variety and skins though, TWS4 is superior.

This is fine. No Living World Season needs to be similar to previous ones. On the contrary, by making Living World Season some what unique Arenanet is both creating an incentive for people to get more than 1 season (thus anchoring people better in the story and encouraging revenue for themselves) and it does not make future Living World Season obsolete for veteran players.

This is in a way similar how Arenanet makes the same gear available via different game modes, but encourages playing specific game modes by making acquisition easier or faster in those. See ascended rings and fractals for example, or ascended accessories via guild mission tokens.

Reward types are way better in Season 4 then in 3.That depends on what your priorities are. In terms of skins: yes, in terms of functionality: no. Problem is: cosmetics don't add any replay value to the maps (well, cosmetic infusions would if you could actually expect to obtain them by farming the content in question), ascended equipment does. There's no point in ever returning to the Jahai Bluffs for mistonium once you got your skins thanks to the Requiem set not being ascended armor, Bitterfrost Frontier on the other hand is still relevant to this day thanks to the high amount of replay value added through the various ascended items. Also, nobody cares about the weapon set since it's tied to crafting. If it was the same as the LWS3 stuff: map currency + LWS4 currency then I would agree but that's not the case here.

You can get an almost free 32-slot bag from Ep2, that's a huge reward for me.