Obviously bountiful delves are amazing, get a piece of decent gear at the end if you have a key, not spammable because of the key mechanics.
Regular delves however have no point. Just ran a t7 delve, other then almost getting 1shot by not paying attention, I was able to get through it on a slightly undergeared (570) toon when they recommend 571+.
Why I am pulling 554 gear out of there? I get that they aren’t supposed to be loot farms, (maybe they are who knows) but dropping gear 17 item levels below the recommended threshold to run them literally makes no sense.