A lot of people fall into the trap of "good build". Almost any skill is viable up until a point. Where that point is changes based on skills and classes. Having ONE character be tanky/clear fast/faceroll ubers is NOT a reasonable goal. My best characters excel at 2/3 of those and USUALLY sacrifice tankiness for omega DPS for mechanics that can be bypassed by DPS like Sirus or Shaper where you can just instantly go next phase.
You'll see a lot of people, streamer farmers included, have a 'starter' build because it'll do everything but ubers and 100% delirius T20 maps and shit. People say melee is dead, but if you just want to complete your main story, get your compasses, and clear all reds you can use basically any melee skill (we're not talking Chain Hook or Heavy Strike). You need something like 500k dps to clear alch and go T16's and in this day and age that just means you need a 5link, an essence weapon, and your uber lab.
It goes back to D2. There were few builds that did everything well, but a lot of builds that excelled at niches. In D2R I played a Frenzy Barb which sucked dick for cows or any density, but could run shit like Countess or named sniping faster than even most Sorcs and Enigma runners. I also had a Corpse exploder necro who could solo Cows no problem, but bone spearing bosses was a pain in the dick. A single build in PoE doing EVERYTHING WELL is just too much. Once that happens meta shift gets even worse and you go from the 15-10-10-9-9-9 type shit in PoE Ninja to go back to the days of 30-15-10-5-5-5 kind of shit. There were literally leagues where 25% of the PoE Ninja leaders were the same skill. That's fucked, but it's because that skill did EVERYTHING. The real reason this shifted was ubers. DD versus ubers is shit. Minions vs ubers are shit. A lot of the big builds are great for clearing/mapping normal bosses, but just cannot do Ubers. I think that's okay.
TL;DR PoE doesn't want ONE build to do every part of the game exceptionally well and people need to plan on making a 2nd character to do some of the harder stuff (re: ubers). The idea of starter builds turn people off, but really they're not starter builds they're just builds that take a lot longer to hit a content ceiling. Most builds can be starter builds if you have reasonable goals like clearing T16's and normal non-uber bosses.