After writing this up I realized its kinda off-topic since its mostly replying to a more general part of the discussion. So here's a TLDR in advance: A PvP game shouldnt have levels that come with stat advantages. Equal footing for all characters is the entry point, then you can pile on the unfairness on the battlefield.
You didnt answer my question. But to answer yours, the scenario had levels because alot of people love them and expect them (and WoW had them, so they're good). It was just a question to better understand what you want, its not actually a scenario I want to be used as game foundation.
Like I said some pages ago I believe the "rush to endgame" is an attitude thats leading MMORPGs in a wrong direction, and the last decade so ingrained it in the player base that the only way to get rid of it is to take away the levels. You can do that your way (no levels at all, just gear), its an interesting approach. Personally I do prefer the EVE system of no levels at all. If a game must use levels, make them effectively endless (D2 went that way with the diminishing returns, nobody went 99 by honest means). UO did skills very different (although that had its own bag of troubles), Planetside uses levels to show how much xp you gained in total but its a pointless statistic otherwise that merely unlocks some titles and rank insignias. You cant take more hits or hit easier just because of your battle rank. The defense/offense boosts that EQ and all its clones included in the level formula are a shortcut to guiding people through PvE, but all games after EQ tried to have PvP and there the level boosts are usually causing problems.
So for this game, a PvP game, no levels like the exist in EQ/WoW/etc is the way to go. GW puts players on equal footing as far as levels go and reserves the levels for PvE (and even there makes them mostly cosmetic with up- and downscaling). Why have them if you go to such lengths to not use them?
The complaints about level come earlier and more because leveling comes first, that's all. People are tired of the gear grind just as much as they are tired of the level grind. In your example, if your new game launches with 10 tiers of gear where you need to advance through them tier by tier instead of jumping from 1 to 4, 4 to7 and then 7 to 10, people would complain as loudly. "People" (gotta put that in quotation marks here) just want to epeen their stats up as fast as possible, and dont you dare to make them play the game for it more then absolutely necessary. Or do you disagree with that impression (not saying you are like that, but "people" are)? Isnt WoW a longterm sucess because it allows people to be caught up from zero within a few weeks? To players expecting that kinda game any long gear advancement chain is too much, no matter how well designed and involving it is. So yea your game would be more popular for a month.