As someone who just started playing this mod recently, I can attest that the progression is one of the most off-putting things about it to me. I honestly think that anyone who believes that this system is fine the way it is only thinks so because they've already finished the grind. When I see that I'll basically have to play for a bazillion fucking hours to acquire equipment that's on a comparable level to the players that are already dominantly more skilled than I am because they've inherently been playing the game for much longer, it makes it hard to want to stick around.
When I get beaten by someone because they're a better player than I am, I can happily accept that. It shows me what I still have yet to master, and I know that if I keep playing against them, I'll learn and become better at playing the game.
However, when I get beaten by someone because they have a +3 fuckhuge sword of murderization and a full set of armor of your-scrub-weapon-does-no-damage-ness, it feels shitty. There's nothing I can do as a player to combat the fact that the other guy just has a straight-up mechanical advantage over me, and closing the equipment gap feels like it'll take an eternity. I don't learn anything about playing the game when I'm constantly getting destroyed by people who just have bigger numbers than I do.
The biggest suggestion I would contribute to this conversation is make it possible to get on the same level as everyone else in an even remotely reasonable timeframe. Most people couldn't dedicate every waking moment of their lives to this mod even if they wanted to. It doesn't draw people in when they can't even participate in the economy without having played for an eternity. It doesn't draw people in when they finally grind on long enough to get a character to level 30 and think to themselves "Oh god finally just one more level and I can retire this guy" only to be met with "HA JK FUCKER DO IT ALL OVER AGAIN!" and "Okay, now you just have to do that two more times and you can have one piece of equipment that's as good as everyone else's!"
I really like this mod, but it's incredibly off-putting when you have to invest a huge amount of time to have stats and equipment that's comparable to the people who can already wipe the floor with you with skill alone.