That’s probably not a good thing and warrants further investigation. Which part are you using? The title suggests an ADS1015 but I see references to ADS1115. It looks like the former can do 12-bit samples at 3300 SPS and the latter can do 16-bit conversions at 860 SPS.
I thought of you OEMers the other day. I’m currently using some STM32 processors on a project unrelated to energy monitoring, but when I discovered the phenomenal ADC performance I couldn’t help but think what a great OEM platform it would make. It can do 12-bit conversions in 1 usec, do a continuous sequence of them in the pin-order of your choosing, and load the results directly into your C datastructure, all without any CPU interaction at all. Imagine an interrupt every 1 msec to say “I’ve just loaded those 1,000 12-bit samples you requested into your first array and I’m currently working on filling your second array with a new 1,000 samples”.