Bombs are a meme. Slow to activate, A over-telegraphed toolbelt skill with very little payoff. Damage that you can simply walk out of. But there are a few aspects to bomb kit that can be oppressive under the right circumstances. Namely:
Smoke Bomb + Flash Shell + Explosive Entrance + Flashbang + Invigorating Speed.
If running tools you can run Streamlined kits for easy access to swiftness, which will proc Vigor from Invorating Speed. You can also run Adrenal Implant for a total of +90% endurance regen when Vigor is up. What this means is more dodges, more flashbang procs, more dazes when the opponent is on high health, and most importantly, more blinds.
If the sidenode meta ever shifts to be more melee heavy this build will frustrate players with its endless blind spam.
Very few people take staff ele seriously. It's an easy kill, but damage, as we've seen keeps creeping lower and lower. Hard hitters like Holo and Rev have slowly been receiving nerfs. Other builds that can bully it like thief have also been getting nerfed steadily. If damage continues to creep lower, this build will make a comeback.
It's a very easy build to gain value on. Simply press Signet of Fire, then press Fire 3. Very little tell, very little cast time. If you have allies to provide cover condis, you can spike people down in no time at all. Afterwards, simpy cycle through defensive cooldowns for 12 seconds until your burst is up again. If allowed to freecast, you have a good amount of AoE pressure crowd control. What makes this build oppressive is it's ease of use. It has a 2 button burst rotation with very little tell that happens from range. It may not see much use in plat, but lower ranks will complain if this starts seeing play.
Supports are a dying breed in PvP. Scrapper, scourge, druid, and firebrand have all received heavy nerfs which have seen their removal from the meta. Should healbreaker and tempest also receive nerfs, this build may eventually rise to the top.
Similar to staff ele, if damage also continues to creep lower, this build's weakness of being focused will become less of an issue. It can heal, cleanse, and even crowd control opponents while being locked down itself. If damage is lowered enough, this build will be able to keep itself alive even in the middle of a CC chain. No other support can do this. You will see complaints such as "make tablet destructable" or "add a cast time to ventari heals. It shouldn't be able to heal itself while locked down".
Counterplay exists for each of these builds right now, but as options are removed, and more builds are nerfed, counterplay will also be reduced. PvPers of the past would have laughed if they saw a Renegade in their game, now it's the hot topic of the forums. Here's hoping I'm wrong.