I have tried many programs and configurations. It’s pretty common that file sizes are about the same with single pass software encoding.Which software encoder did you use? Which codec? Which Profile? Settings?
If you just used a mediocre to poor software encoder (Adobe, Apple, etc.), that may be. With a very good software encoder, like x265, this contradicts my own experience and those I've read about (e.g. here, Handbrake forum, etc.).
Like I said, it really doesn’t matter. It’s not like the file size is 100MB with software encoding but 700GB with hardware encoding. The best difference I have seen in my workload is when I configure it for multi pass and very slow software encoding. But that makes my export take two days. Yes 48 hours for ONE PROJECT. Compared to 5 hours hardware.
I have 150TB NAS. Getting a second one. Storage is relatively cheap these days. I would rather use hardware encoding than software when I can’t even tell the difference visually.