ES actually has better single target / small pack DMG than AoE. Fire warlock is better at density clear than ES. So the real question is more Light/Nova sorc vs Fire warlock than ES warlock
blood boil >
anyway
An all-in glass cannon lightning build (not the hoto/spirit of OP) has about the same pierce and DPS as blood boil does when you include defiler buff, and without defiler its about 2/3 of the DPS but in an obviously much better un-aimed giant aoe around you. And when you can have 25k swap-on-enter gear demon (~18k without) and that's not only multiplied by defiler but also becomes splash aoe damage, that actually deals a whole bunch more dps than lightning even if its only hitting every 23 fpa (but 3x hits for spearwomen)
The OP's low pierce 105 build for example hits 22.3k lightning at 8 fpa. If a monster isn't immune or a 75 resist venom lord then -40% pierce and conviction is enough to get them to -100 and deal 44.6k. While against immunes it deals 14k. But more damage-focused builds should have way more pierce and get into the ~20k vs immune range. Meanwhile blood boil goes up to around 12.9k damage in 4.8k phys + 8.1k fire, with amp, sigil, conviction & 55% pierce, but also 56% defiler bonus. So against punching bag nonimmunes its up to 25.8k before defiler, 40.3k with defiler, and even against a 50% dr fire immune it can be 15k before defiler, 23.4k with. And that's not including the demon whacking its 18-25k phys at 23 fpa or a spearwoman is probably closer to avg 15 fpa, dunno jab frequency.
When it comes to density clearing there's just an invaluable advantage to having a spell that requires no aiming and hits in every direction with a huge aoe. That's the advantage of Nova, but its only ~60% of the aoe of blood boil. Lightning hits for more focused damage in a line that can't hit whole screens at once and misses targets and leaves you surrounded on sides, and you can't tank big packs like heralds like any warlock can for free. BB is like the dps of lightning in an aoe nearly twice that of nova. ES is in a similar boat to lightning for AoE, yeah its a bit conical and persistent but less wide / less range, and its advantage is really just in killing those P8 TZ96 T5 heralds with their 3000% hp because all the other builds- lightning, nova, es, fire, etc- have plenty sufficient DPS for any P8 packs or content but start to slow down against baal/ubers/heralds even if they
can kill them.