Previously this happened multiple times. When you left T1 for T2, you sucked. Left T2 for T3, you sucked. Leave T3? Well now you're R32 fighting people in SOV gear. Not to mention T2/T3 would often suffer ZERO SC pops or RvR action for days at a time, leaving newbies to effectively level solo in PvE.
New system is FAR preferable. So, remember that when you complain about it. You get a Bolster which is determined by your gear. If you actually look when pvp flagged, you'll notice you have awesome stats. Your main attack stat(int/bs/str) will be nearly softcapped(for your lvl) and your wounds/tough/resistances will be close to cap also. Stack wounds tali's, and you're actually tankier than you will be at higher levels. You hit like a wet noodle, but you're a lowbie. If the Bolster actively made lowbies threats to RR80 toons, then wtf would be the point in going to RR80? Bonus Points: Check out your PvP stats on a WH/WE lvl 1. Check out what your parry rate is, and THEN tell me the bolster isn't effective... Same goes for R16 upwards, it's just not as dramatic. W/o that bolster you'd get literally 2 shot by AAs.
I dislike the SC system of 16-39 all in one tier. But blame the playerbase for that. You have to fight RR80's at some point, it was decided at R40 was the best time. So what're you gonna do? Split up the Tiers and you get dead zones, no one wants to play in a deadzone tier, so lets all play together in a kinda fun tier instead.
You are lvling in a MMORPG game. Power spikes and power dips happen. If lvl 16s in green PvE gear had a chance or could threaten 39/60+s in Anni gear then you'd have people uninstalling because the game is just a huge waste of time. Why bother lvling or gearing up, when a 16 in bolster can rock you? Get more ranks and gear. Understand how stats are actually adjusted and what baselines you need to meet. IE, go learn the game a bit more. You'll be fine.
last point; Archetype matters. If you are a healer/tank then once you hit 20(earlier if Secrets is giving away a secret(har har)you're pretty much good to go, and it's positioning/tactics that you need to learn more than anything. DPS classes are different. DPS is very heavily gear/RR dependant. But, more than anything, it needs to be played "right". The worst DPS class(DPS Zealot imo) can be effective, as long as you assist off other DPS classes. I never see anyone do this in low tiers(and few in t4). My Sorc when I was lvling was almost always top DB in SCs, cause I set my assist to the "best" dps in the SC. Since no one else assisted, I got kills left and right. Just play the game with a group mentality, and learn when to push which button and you'll be fine.
TLDR; Lvl 16 is supposed to kinda suck. Same as lvl 1 does. We all wish we had the population for a full 4 tiers. We don't. We have a bolster. If you think it should be improved, plz offer specific advice as to how. And if you are actually new to the game, life is gonna be hard. This is a very complicated game, that isn't super well documented, and has a slightly toxic playerbase. New players will have to put in serious effort. That's how MMO's work...
Edit: as for fighting the same prem over and over... Try placing this in chat: