H.264 exports too big

Hi there, I've been trying to figure out why lately it seems impossible to get a video exported with a low file-size without sacrificing all of my quality. I know length is a huge factor, but I'm not doing anything more than 5 minutes long, often under 2-3 minutes.

This is an issue if I'm rendering 4k footage, or 720 footage. Both are too large when exported. 4k is larger, but 720 anything in 2018 shouldn't be getting me 750mb files....should it?

I match the sequence settings to the export format I intend to use, and it seems to make little to no difference.

I like to use h.264 and use the match source - high bitrate setting, then I'll do a vbr 2 pass setting the minimum to 8 and the target to 20 or 25. This is usually a good balance between file size and quality, but lately I can't seem to get anything smaller than 500mb or more. I know I can turn the target bitrate down to significantly reduce the size, but it proportionally reduces the quality, which is not the aim.

This didn't used to be an issue for me personally, as uploading something that size to a video site is usually fine (not that I wouldn't want smaller file sizes for that) but now I have to send these videos internally for people to review before they're up on a site, and unless I want something unwatchable, I'm forcing people to download 500mb - 1 gb videos just to preview and review them...they aren't thrilled.

I used the MPEGII shell for years, and that always seemed to get me low file size with high quality, so I thought I'd see where that's at these days, but that makes the files even bigger.

Is this just how it is now? Did something significant change? H.264 is prided as the solution to small video files with high quality. I feel like I missed something big in recent developments with premiere and media encoder.

It's only recently that it seems like small video size with little to no loss in quality is extremely difficult to achieve.

Anybody have a cheatcode on this one?